I have been experiencing recurrent UI freezes on the Linux Steam version of Transformice, usually when a RAM-heavy process (such as YT on Firefox) is running but sometimes it happens with no other programs being open. The game doesn't exactly become unresponsive when it happens as I can *still* interact with the UI; it's rather the game refusing to update window contents. The issue is present on both AIR and Electron versions.
I have reported this issue before on the Discord server but it didn't get any attention so far.

This is something only experienced by you and not by other players in the room? I'm asking because there have been occasional freezes lately where the game becomes unresponsive for a while and the mice don't move on screen anymore (and some players may get disconnected), but the UI often still works. In those cases, the probem is more likely server-sided, and not related to which game version is used.

If you think it's just you, you could try if this also happens when using a standalone Flashplayer (or a browser, if you still have one with a Flash plugin) with the game's online loader instead of the Steam or Electron version, to find out whether the problem is caused by those Air applications, or something else on your computer (hardware- or software-related).

I have described how to do that here:
https://atelier801.com/topic?f=6&t=854970&p=5#m90

The issue is client-side and is only present in the official (Steam) clients. The unofficial Linux client, which also uses Electron, is not affected. I had been using it without issue up until the retirement of the browser version as it, being just a middleware that provides access to the browser version, was also hit by the EOL experience degradation.