2 more cents :)
I’ve been using syncthing for a while now, on different devices, and the only unreliability I’ve run into is with android killing syncthing to save battery life, which is kinda hilarious, considering all the vendor- and google-provided crap they happily waste battery on (I don’t use it, but for what I’ve heard iOS is even worse in this regard).
Specifically, I have a samsung tablet where, no matter how much I tinkered with system settings, synchthing would only run if I manually launched the app or while the tablet was charging (BTW I still use that same tablet, but it now runs LineageOS and syncthing works flawlessly).
All this is to say, you should probably look into system settings and research ways to convince your OS to do what it’s supposed to rather than tinkering with syncthing itself.
I fear it was nothing that entertaining: it was just my “normal” dark panel at the top of the screen and a second “default” white one at the bottom (this last one partially covered the windows I had open). I didn’t try triggering notifications or otherwise causing some kind of mayhem.
I’m just messing around with testing/configuring different desktop environment/window managers and I’m looking for a quick way to preview them (running the new session as my user would be fine too - I just thought it would be simpler as a different user)
Wow, that’s so neat!
On my machine it opens a fullscreen plasma spash and then it shows the new session intermixed/overlayed with my current one instead of in a new window… basically, it’s a mess :D
If I may abuse your patience:
startplasma-wayland
from a terminal as your user? (I see the plasma splash screen and then I’m back to my old session)
For those kind of issues I’d recommend snapshots instead of backups