I am using Flirc USB on Ubuntu and I can program it and it works (using a single Harmony remote) and only controlling Kodi.
However, I am getting constant seemingly random IR signals, some of which seem to result in keypresses or control characters or something which really messes with the PC. You can't really use the PC with this going on.
If I look at the device log and enable IR debugging then I can see all these signals being received but if I leave a cursor in an editor I don't get any visible keys or anything showing, it's very odd.
I have tried the flirc on various USB ports, with/without USB extension cable. I have tried the flirc in different rooms, in cupboards, covering the Flirc completely so it cannot possible be seeing any IR signals. I have tried disabling all builtin profiles (I normally just have the kodi one enabled).
I have read on here lots of (very old) problems like this but no real solution.
Flirc GUI v3.24.1
An example log from just a few minutes:
Mon Nov 25 2019 17:14:47
Flirc GUI Version v3.24.2
Operating System: Linux