Atem Mini PRO ISO: certain buttons in software have no text

I recently bought an second hand Atem Mini PRO ISO.
For some unknown reason some buttons in the software show no text but are not grayed out.
When clicking on the buttons they also work (color, colourbar andso).

I updated the Atem Control Software to the latest 8.7 and forced the Atem itself to update.
But the Atem stays on software 8.6.1. (I thought that the firmware of the Atem was always the same as the software of the Control Software ?).

Any idea how to get text in the buttons ?

Solved with help of the Blackmagic forum:
“Somebody removed all text labels under Settings > Labels > Output”