Drag and Drop Questions don't work when created on Firefox (on Ubuntu)

[SamuelRoettgermann]

Describe the bug

When creating a D&D question in Firefox 143.0.3 (64-bit) and Ubuntu 24.04, the process works mostly correct, up until the point where you hit the "Cut Images from Drop Locations", at which point the background disappears, and any cut images that are larger than about 40x40 - 50x50 (which, by the way, looks more like a 40x80 and 50x100 respectively) - the exact number is hard to determine as it's a bit flaky in that range - but every rectangle larger than 55x55 definitely breaks.

Please view the screenshots to get some understanding of what I exactly mean (first is before hitting the "Cut Images from Drop Locations", second is immediately after that):
Before cutting:

After cutting:

This behaviour is only the case if the D&D question gets created in Firefox, if the question was created in Chrome, everything works perfectly in both browsers, but if the exercise was created in Firefox it's broken not only in Firefox, but also in Chrome, indicating that this bug actually leads to wrong information being stored, and the background is also gone in Chrome. In fact, here is how the Chrome "Show Result" view looks like (different testing run than the first 2 images):

That being said, I did only test Firefox and Chrome, due to a lack of other browsers.

To Reproduce

1. Start Firefox
2. Go to a course where you are at least instructor
3. Create a new exercise
4. In that exercise create a new Drag and Drop question
5. Select a background
6. Draw any rectangles or don't
7. Hit the "Cut Images from Drop Locations"

Expected behavior

Background shouldn't disappear, and images should not be messed up

Which version of Artemis are you seeing the problem on?

8.4.2

What browsers are you seeing the problem on?

Firefox