it’s a lot of work to switch distributions, and I don’t recommend unless you have a really good reason!

kde is supported on Ubuntu… id suggest installing it and trying it out first. the bugs u state sound like desktop environment issues and not distribution bugs …

1. syncthing (file synchronization)
2. kdeconnect (file transfers, clipboard sharing, presentation remote)
3. deskflow (keyboard and mouse sharing)
4. warpinator (one off file sharing)
5. rsync / scp (one off file copies / backups)