I don't where this issue comes from, but it could be the problem with loading saved games. I've tried to look alot into this, but I can't find a clear solution. The save-game bug occurs to me when I load a save game and then press the backwards button before clicking on any link (or when clicking on a link that has a 'back' link button). My work-around for this is now to load a game and then just click on some location links to prevent this.
As far as the issue with Keisha, the scenes should reset after sleeping on a sunday, so sleeping for a whole week, then visiting on friday morning, then the day directly after that, visit her saturday morning. If this doens't work, Goonie gave a good solution right here:
Hope this helps. If not, please send a DM to me.
Kind regards,
Clownpron