Copied drivers corrupted my scene?

I created a shape keys and drivers.
Then I created new versions of the same shape keys and copied the old drivers to the new ones.
I made sure the name of the shape keys that were used in the variables of the drivers were correct.
Then I change the frame and the box of the variables path becomes red…
I click Check Dependencies, it turns black, it seems fixed…
But when I change frame again the path becomes red again…

I tried recreating the variable, same result
I tried recreating the driver from scratch, same result.

I also don’t get why all the old drivers are still listed with a red underline…

I just found out that if I delete the subdivision modifier the problem is gone… But comes back if i put a new one.

I also found out the problem is gone if i do a full copy of the scene, but if i do this i have to rename all my stuff cause it adds 001 at the end of everything. I know i can use the renamer but still…

The problem also doesn’t happen in 2.91 or 2.92… It happens in 2.90.
I would use 2.91/92 but in them i have another bug where i can’t change actions for the armature…
It doesn’t happen in 2.83 or 2.90…

So this is pretty confusing.
Is there any big changes between how armature/actions/drivers are calculated between 2.90 and 2.91?