Keystone bug in Midnight Burrows

[Roxaerio]

I collected all the keystones in the midnight burrows but when i went to open the door the game only thinks i have 3/4 of the keystones. The thing is all of the keystones icons disappeared from my map and from the surrounding. This is incredibly frustrating. It took me a while to get the last keystone only to find out the game thinks i dont have it.

If this had happened in a non-optional area I'd be furious. Can somebody please help with this?

[Nibbie]

Have you tried loading a back-up save?

[GSandSDS]

Ignoring the map (it is just possible that the map does not show the 4th keystone), do you find all 4 keystone holders? If yes, did you maybe use one of the 4 keystones for another gate outside the Midnight Burrows?

[Spirit]

interestingly i was able to find all 4 of the keystones without issues

[DIZZI]

I am also experiencing this bug, have tried everything :/