SUMMARY
At a x64 tablet, manual rotate works, but the screen display will do, the touch screen will not. So vertical finger movements lead to horizontal pointer movements and vice versa.

STEPS TO REPRODUCE
1. system settings  > display&monitor > screen orientation > rotate by 90°


OBSERVED RESULT
Screen display will rotate, the touch screen will not. So vertical finger movements lead to horizontal pointer movements and vice versa, position of mouse pointer will no longer match finger position. 

EXPECTED RESULT
Position of mouse pointer will always follow finger position. 


Operating System: Manjaro Linux, kubuntu 18.04 & 19.10
KDE Plasma Version: 5.17.5
KDE Frameworks Version: 5.66.0
Qt Version: 5.14.1
Kernel Version: 5.4.18-1-MANJARO
OS Type: 64-bit
Processors: 4 × Intel® Celeron® CPU N2920 @ 1.86GHz
Memory: 3,7 GiB


ADDITIONAL INFORMATION
This is not about "auto rotate".