I don’t think you’ve tried it on Wine 6, correct? I recommend using synaptic to Completely Remove the existing Wine and then installing 6 for 20.04 using winehq. Note that if you get the GLXBadFBConfig error, you need to apply the POL console shortcut edit fix I mentioned earlier.
Using Synaptic to remove Wine 5 should ensure all old files are removed. These could be adding to the problem. Without synaptic I recall I had to hunt around for the wine folders in the home directory (and use ctrl+h to show the hidden ones).
Coincidentally, I ran picasim, last night. It’s pretty good. Reminds me of Realflight. I ended up doing a few minutes of hovering on a 3D indoor model - an indoor profile foamie also happens to be one of the three planes left in my fleet.
The Tx setup requires registering each channel under its own “joystick” channel on the joystick tab of the settings menu. Not hard but I thought I’d mention in case you get it running and wonder why the Tx isn’t recognized.
Anyway, let me know what happens after you upgrade to Wine 6 (but only after completely removing version 5).