2019.4.32 Linux player see's mouse down doesn't call onclick for button

Trying to update our 5.6.7 kiosk-like project to 2019.4

We have a bare bones ubuntu install originally 14.04 then18.04 and now 20.04. It is just X with no windows manager. We have 2 screens with 2 touchscreens in mouse mode. We run an app on each screen so each app has one screen and one mouse input.

In all OSs with unity 5.6.7 everything works. With unity 2019.4 buttons don't seems to work.

I made a test project with a button and a few text boxes. I can see the mouse X&Y changing as you touch the screen. On each touch I see the mouse button down, but it never seems to call the on click for the button.

In the editor on windows, or the player in a desktop linux (20.04 with boot stick) it works just fine. So there is nothing wrong with the test project.

Is there a dependency that Unity 2019.4 needs for the onclicks to work? A full desktop is just not something we can really do for this project.