Reinitialize third party keyboard
Solution 1:
I found a solution. If anyone stumbles over this thread (Thanks to TOM - see: https://m10lmac.blogspot.com/2009/12/fixing-keyboard-type-problems.html):
Remove the keyboard file (see command), unplug the USB keyboard and reboot. Reconnect the keyboard which opens the keyboard detection assistant.
Command:
rm /Library/Preferences/com.apple.keyboardtype.plist
Solution 2:
Try going to System Preferences -> Keyboard and click the "Change Keyboard Type..." button in the lower left corner. This should restart the keyboard type detection.
