I always used to be able to get the participant ID using query parameters, but, now as you can see (image of csv data sheet attached), inquisit spits out these weird characters. I don't think I am doing anything wrong since every so often it spits the correct participant ID (i.e., '240'). What to do?

It's not possible to say where / what the issue may be without seeing the actual set up of the web script. Would it be possible to share the link to the experiment's start page here, please?

Of course.
Here is the link: https://mili2nd.co/2clb

Thanks for the link. Given how things are set up, I assume you have participants start with Inquisit and then want to redirect them from there to a Qualtrics survey, passing the subject number randomly generated by Inquisit over to Qualtrics. Is that correct or is there some other component prior to the Inquisit Web part?

If not, the setup looks generally okay, although there is one thing that doesn't quite seem right. You've indicated

https://gmuchss.qualtrics.com/jfe/form/SV_bJaXzG9gIVmPNWZ?subjectid=<%script.subjectid%>&id=%SURVEY_CODE%

as the URL to redirect to in your web experiment's settings. Now, the bolded part is not something Inquisit knows about and would just produce garble (there is no such thing as a %SURVEY_CODE% placeholder / variable in Inquisit). Where is that coming from and what is the purpose?

At any rate, there is an alternative way to specify a URL for redirection, and whether that resolves the problem (although I'm unable to reproduce it) is worth trying. You can have your script set the redirection directly instead of putting it in the web settings, i.e, you can do

<text finishURL>
/ items = ("https://gmuchss.qualtrics.com/jfe/form/SV_bJaXzG9gIVmPNWZ?subjectid=<%script.subjectid%>")
</text>

or

<text finishURL>
/ items = ("https://gmuchss.qualtrics.com/jfe/form/SV_bJaXzG9gIVmPNWZ?subjectid=<%script.subjectid%>&id=%SURVEY_CODE%")
</text>

(if the id / SURVEY_CODE parameter needs to be there for some reason, although Inquisit won't be able to do anything with it)

with

<expt>
/ onexptbegin = [
defaults.finishpage = text.finishURL.item(1);
]

/ onexptbegin = [
list.human_uprightitems_repeatedupright.appenditem(list.nitems.nextindex);
list.human_uprightitems_repeatedupright.appenditem(list.nitems.nextindex);
list.human_uprightitems_repeatedupright.appenditem(list.nitems.nextindex);
list.human_uprightitems_repeatedupright.appenditem(list.nitems.nextindex);
list.human_uprightitems_repeatedupright.appenditem(list.nitems.nextindex);
list.human_uprightitems_repeatedupright.appenditem(list.nitems.nextindex);
list.human_uprightitems_repeatedupright.appenditem(list.nitems.nextindex);
list.human_uprightitems_repeatedupright.appenditem(list.nitems.nextindex);
list.human_uprightitems_repeatedupright.appenditem(list.nitems.nextindex);
list.human_uprightitems_repeatedupsidedown.appenditem(list.nitems.nextindex);
list.human_uprightitems_repeatedupsidedown.appenditem(list.nitems.nextindex);
list.human_uprightitems_repeatedupsidedown.appenditem(list.nitems.nextindex);
list.human_uprightitems_repeatedupsidedown.appenditem(list.nitems.nextindex);
list.human_uprightitems_repeatedupsidedown.appenditem(list.nitems.nextindex);
list.human_uprightitems_repeatedupsidedown.appenditem(list.nitems.nextindex);
list.human_uprightitems_repeatedupsidedown.appenditem(list.nitems.nextindex);
list.human_uprightitems_repeatedupsidedown.appenditem(list.nitems.nextindex);
list.human_uprightitems_repeatedupsidedown.appenditem(list.nitems.nextindex);

list.android_uprightitems_repeatedupright.appenditem(list.nitems.nextindex);
list.android_uprightitems_repeatedupright.appenditem(list.nitems.nextindex);
list.android_uprightitems_repeatedupright.appenditem(list.nitems.nextindex);
list.android_uprightitems_repeatedupright.appenditem(list.nitems.nextindex);
list.android_uprightitems_repeatedupright.appenditem(list.nitems.nextindex);
list.android_uprightitems_repeatedupright.appenditem(list.nitems.nextindex);
list.android_uprightitems_repeatedupright.appenditem(list.nitems.nextindex);
list.android_uprightitems_repeatedupright.appenditem(list.nitems.nextindex);
list.android_uprightitems_repeatedupright.appenditem(list.nitems.nextindex);
list.android_uprightitems_repeatedupsidedown.appenditem(list.nitems.nextindex);
list.android_uprightitems_repeatedupsidedown.appenditem(list.nitems.nextindex);
list.android_uprightitems_repeatedupsidedown.appenditem(list.nitems.nextindex);
list.android_uprightitems_repeatedupsidedown.appenditem(list.nitems.nextindex);
list.android_uprightitems_repeatedupsidedown.appenditem(list.nitems.nextindex);
list.android_uprightitems_repeatedupsidedown.appenditem(list.nitems.nextindex);
list.android_uprightitems_repeatedupsidedown.appenditem(list.nitems.nextindex);
list.android_uprightitems_repeatedupsidedown.appenditem(list.nitems.nextindex);
list.android_uprightitems_repeatedupsidedown.appenditem(list.nitems.nextindex);

list.upright_test_items.appenditem(list.nitems.nextindex);
list.upright_test_items.appenditem(list.nitems.nextindex);
list.upright_test_items.appenditem(list.nitems.nextindex);
list.upright_test_items.appenditem(list.nitems.nextindex);
list.upright_test_items.appenditem(list.nitems.nextindex);
list.upright_test_items.appenditem(list.nitems.nextindex);
list.upright_test_items.appenditem(list.nitems.nextindex);
list.upright_test_items.appenditem(list.nitems.nextindex);
list.upright_test_items.appenditem(list.nitems.nextindex);
list.upright_test_items.appenditem(list.nitems.nextindex);
list.upright_test_items.appenditem(list.nitems.nextindex);
list.upright_test_items.appenditem(list.nitems.nextindex);
list.upright_test_items.appenditem(list.nitems.nextindex);
list.upright_test_items.appenditem(list.nitems.nextindex);
list.upright_test_items.appenditem(list.nitems.nextindex);
list.upright_test_items.appenditem(list.nitems.nextindex);
list.upright_test_items.appenditem(list.nitems.nextindex);
list.upright_test_items.appenditem(list.nitems.nextindex);


list.upside_down_test_items.appenditem(list.nitems.nextindex);
list.upside_down_test_items.appenditem(list.nitems.nextindex);
list.upside_down_test_items.appenditem(list.nitems.nextindex);
list.upside_down_test_items.appenditem(list.nitems.nextindex);
list.upside_down_test_items.appenditem(list.nitems.nextindex);
list.upside_down_test_items.appenditem(list.nitems.nextindex);
list.upside_down_test_items.appenditem(list.nitems.nextindex);
list.upside_down_test_items.appenditem(list.nitems.nextindex);
list.upside_down_test_items.appenditem(list.nitems.nextindex);
list.upside_down_test_items.appenditem(list.nitems.nextindex);
list.upside_down_test_items.appenditem(list.nitems.nextindex);
list.upside_down_test_items.appenditem(list.nitems.nextindex);
list.upside_down_test_items.appenditem(list.nitems.nextindex);
list.upside_down_test_items.appenditem(list.nitems.nextindex);
list.upside_down_test_items.appenditem(list.nitems.nextindex);
list.upside_down_test_items.appenditem(list.nitems.nextindex);
list.upside_down_test_items.appenditem(list.nitems.nextindex);
list.upside_down_test_items.appenditem(list.nitems.nextindex);



]

/ blocks = [
1 = intro_Attention_Check;
2 = intro_1;
3 = intro_2;
4 = intro_3;
5 = intro_4;
6 = intro_6;
7 = intro_7;
8 = intro_8;
9 = intro_5;
10 = human_android_upright;
11 = testingphase;
12 = human_android_test]

</expt>

I've attached a version of your script that does that -- please give this a shot at your earliest convenience and let me know if it makes any difference as far as the transfer of the subject ID is concerned.

Sorry for the late replay, I've been on leave from school. I tried the code and it worked! Thank you so much.
In regards to the '&id=%SURVEY_CODE%' query parameter, I use it to capture the anonymous codes university students are assigned when they open my survey through the university's online platform (perhaps you've heard of it, it's called 'SONA') so that when they are redirected back to that website after participating, they are automatically given credit for participating in my study, as explained in this website: https://www.sona-systems.com/help/qualtrics.aspx.