Matchbox keyboard on 2.8.4 debian10 doesn't work

I installed matchbox, works fine on linux but after starting gmoccapy it does not show me the keyboard, there is a window in which there should be a keyboard but there are no keys (picture), maybe someone knows the solution to my problem.

 
 

Yes, this seems to be broken in LinuxCNC 2.8.4. I guess you don't know either which was the last version Gmoccapy worked with matchbox-keyboard?

But why don't you use onboard? It can be configured in many ways compared to matchbox-keyboard.

Good question, I hadn't thought of that, so I'm about to install onboard,
Thanks