Such a buggy game.

Another question,

At the daedric altars you can of course offer stuff to the gods, or my character does. Will these items vanish eventually or will they stay there on the shrine?

Items you drop have been known to stay.

All right thanks.

I did put Melyn's Grimoire at Azura's shrine and didn't want it disappearing. Rem collects interesting and unique books, leaves them as offering to his gods, but I also don't want to risk losing the unique looking items either.

I made it look all poetic too

I put the Grimoire, then a red apple on top of the Grimoire, with a Potion of Fire and Cold Resistance standing right next to each other. And a few soul fragments to make it look shiny and pretty. I didn't want all my work to be for nothing.

They will stay there. But depending on the item, it might "move." Most misc items are stable. But armor and weapons tend to move when you re-visit the place.

Well that makes me happy. I just had to make sure they would stay.

I remember dropping a bottle of Honningbrew Mead on the ground after using it to get the Charmed Necklace from the Revelers. Next time I walked by the area, it was floating in mid-air. Gives a whole new meaning to the term 'light beer'.