ZZESTO

Wow @tuanphan, that fixed it immediately. Thnx!

You have this code in CSS box, it caused problem
* { transform: unset !important; transition-delay: unset !important; transition: unset !important; } Change it to this
*:not(.top-bun):not(.patty):not(.bottom-bun) { transform: unset !important; transition-delay: unset !important; transition: unset !important; }  

I try to use existing functionality when possible so as not to reinvent the wheel, if it makes sense in the context of the project.
Working with Squarespace's latest forms can be a major pain and a lot more work than it used to be. Some tasks currently seem impossible with the new internationalized forms. It all depends on the needs of the project.
I would use LocalStorage instead of using cookies. It is easier to work with. If you do end up rolling your own.
There isn't an issue using cookies or LocalStorage functionality itself. It is getting that info into SS forms that can be problematic with SS's new internationalized forms. There are several threads covering some of the pain points of the new forms. I don't have any specific pointers to them.

@Nikta
I believe this is what worked for me:
  * {     transform: unset !important;         transition-delay: unset !important;     transition: unset !important; }  

Thanks for the prompt response.
I feel obligated to point out that if I provide a link to my site and the password here, then literally anyone on the internet can access it. This forum is visible to anyone. Technically, that would qualify as "insecure" if I am trying to keep content hidden. If this is a necessary procedure for diagnosing technical problems, then a more secure solution is required.
However, since I don't have any content I actually need to keep hidden at this point, I am happy to oblige. Here is the blarg link:
https://maracas-lilac-epl4.squarespace.com/blarg
The password is: thisisnotactuallysecure
This is default content, right out of the template. I turned off site animations globally in the theme settings as described above.

Did you ever figure out this issue? I am having the same problem! Thanks in advance.