Extra mouse buttons stopped working after update to Kubuntu 20.04

Question

I recently upgraded from Ubuntu Studio 16.04 to Kubuntu 20.04 (installed fresh on new partition), and after this the two thumb buttons on my GMX 5 mouse stopped working. When using Ubuntu 16.04 I never had to do anything to get them working, just plugged in the mouse and the buttons were immediately recognized in xev and I could use xbindkeys to set them to desired keyboard presses. When I run xev in 20.04 and press the thumb buttons I only get this:

KeymapNotify event, serial 39, synthetic NO, window 0x0,
keys:  4294967236 0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   
       0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0

Instead of the expected output when pressing a mouse button.

When running xinput I get this, I find it curious that the mouse seem to have two entries under pointer and three under keyboard:

⎡ Virtual core pointer                          id=2    [master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
⎜   ↳ E-Signal USB Gaming Mouse                 id=8    [slave  pointer  (2)]
⎜   ↳ E-Signal USB Gaming Mouse Consumer Control        id=11   [slave  pointer  (2)]
⎣ Virtual core keyboard                         id=3    [master keyboard (2)]
    ↳ Virtual core XTEST keyboard               id=5    [slave  keyboard (3)]
    ↳ Power Button                              id=7    [slave  keyboard (3)]
    ↳ Power Button                              id=6    [slave  keyboard (3)]
    ↳ E-Signal USB Gaming Mouse Keyboard        id=9    [slave  keyboard (3)]
    ↳ E-Signal USB Gaming Mouse System Control  id=10   [slave  keyboard (3)]
    ↳ Eee PC WMI hotkeys                        id=12   [slave  keyboard (3)]
    ↳ E-Signal USB Gaming Mouse Consumer Control        id=14   [slave  keyboard (3)]
    ↳ AT Translated Set 2 keyboard              id=13   [slave  keyboard (3)]

When running xinput query-state for the two pointer id:s 8 and 11 I get different results, 8 reports buttons 1-9, while id 11 only reports 7 buttons, I wonder if this has any significance?

What can I do to get the extra mouse buttons detected again?

Answer 1

Problem is solved now, I was thrown off by the output from the thumbbuttons in xev being different from the regular buttons. When testing in 16.04 I discovered that it was supposed to look that way in xev. The actual problem was that I thought I had installed xdotool but actually hadn't, causing xbindkeys to not be able to translate buttons to keypresses.