Re: Lost ability to configure Desktop both dispays after recent update
Same problem here 
The QT bug link is here: https://bugreports.qt.io/browse/QTBUG-86604
As suggested on that bug, running fixes the problem (for me) until next reboot.
Cris
Desktop: OpenSUSE Tumbleweed (x86_64) - AMD Ryzen 5 3600 Six-Core Processor, 16Gb RAM, 120GB Samsung Evo 840 SSD, 500Gb WD BLACK SN750 NVMe SSD
Laptop: OpenSUSE Tumbleweed (x86_64) - Thinkpad T440 - Intel i5-4210U, 12Gb RAM, 250GB Samsung EVO 750 SSD