Hello, I tried to use kubuntu about two months ago but uninstalled due to this specific problem (I thought it would've been fixed in some way by now). I already tried to disable the "upower" service like the troubleshooting section of https://wiki.archlinux.org/index.php/KD ... w_to_start explained but still no luck. I'm pretty new at this kind of stuff so if I'm missing something extremely obvious I apologize lol thanks in advance.

remote mountpoint (smb/nfs) or issues building ksycoca.
Try to run dolphin from konsole and check whether it prints where it stalls.