Hello,
Random questions and/or notes:
Looks like your system is/(was?) Plasma5, please add the info while posting feedback(s) in future
kind of expected in some way… sddm got a major update so in this particular case needs to be dsync-ed from failsafe session or virtual terminal after logout 
for checking the checksums; that’s a crucial step.
How did you transfer the ISO to the USB stick?
https://wiki.openmandriva.org/en/distribution/releases/rome/notes#booting-from-usb
Please disable any additional repository except main before starting the system distro-sync. You can re-enable them later.
The package pyside can be removed before upgrade to avoid such conflicts and re-installed later if needed
Also you may want to read this topic before upgrade ROME
ROME major upgrade expected
Other interesting readings are in the Italian forum, where there is pretty good interaction with users reporting issues and getting instructions 
Use online translator if any need
I’d start looking for “Aggiornamenti di <month_here> 2024”
https://forum.openmandriva.org/search?q=Aggiornamenti%20di
All that said, here is the latest ROME Plasma6 ISO for x86_64.