I wasn't able to reproduce it on the same OS and browser versions so it must be something else. But I have a few hunches what it might be, so just one last thing if you would be so kind as to check if any of the test builds below work, thank you.
(edit: removed the links)
Hi! Thank you very much for the test links! I just tested with my computer but unfortunately none of them work. It’s likely the problem with my browser. I now went on my phone (Android, also with firefox) to see if any of them works, turns out they all work great, including the original game. When I go back to your older games from the browser, they all froze up as well which they did not previously. So it must be the problem from my side. I’m sorry for the trouble. But yeah still looking forward to seeing your new stuff :D