I had this happen once and it was cheap lights that got confused and suddenly started reacting to commands for other addresses. Took me quite a while to figure this out before just throwing them all out.
Starting with the first 2 assumptions, is anyone aware of a means to listening into the ZigBee network to see which device, bridge or middleman, is sending these on/off commands?
I had the same issue with PINCE not restoring the correct memory addresses on start.
Although I think I'm doing something wrong and the memory in modern games is just dynamic so the correct location can't be found with just the memory addresses. Haven't looked if it is possible yet but I assume you need some pattern matching to find the right address, not sure if PINCE can do that yet.
It's fairly straightforward nowadays and will get even easier this year.
In KDE, you can just enable HDR and hit apply. There's also a calibration tool integrated that is a little bit barebones but it does the job.
For gaming, you currently still need Proton-GE until Valve's Proton ships with the necessary libraries. You can easily download them using ProtonUp-Qt.
Once that is done:
Restart Steam
Right click the game -> Properties...
Set the launch options to PROTON_ENABLE_WAYLAND=1 PROTON_ENABLE_HDR=1 %command%
Under Compatibility set the checkmark "Force the use of a specific Steam Play compatibility tool" and select the Proton-GE version you just installed before.
If we're talking about online editing, Collabora has web editors based on LibreOffice but with a modern UI: https://www.collaboraonline.com/
They are really great and can be self hosted (e.g. with Nextcloud).
For offline editing, as already mentioned, LibreOffice has an optional ribbon UI and OnlyOffice looks pretty modern as well.