It's quite the same problem here... I import and edit my photos directly in LR for Android). Had to reinstall LR after an OS update... cloud library synced normally, but now I can't see the Before state (originals)... when long pressing any photo, nothing happens. It works fine when I open in a Windows PC version, but in Android, don't.
Any clue on how to fix this? I tried to reimport, nothing happens... the only way is copying the edit settings, delete the photo, import original again and paste the settings... but this is not suitable when you have tons of images...