Do you happen to have any issues exporting your audio out by any chance? And is yours across all files or just one?
I have a file I did some work in last night that is experiencing the same horizontal scroll issue and I can't export audio without it locking up.
I opened the previous version I'd saved of this file from a few days ago, and it still functions fine (no scroll issue and exports fine). I made no large setting/configuration change before saving this file. I just did some light editing...recorded a few things and tweaked some VST track notes.
