Jailer Key

[Solid Snake]

I defeated the jailer and got his key. But after leaving the area, whenever I go to the doors where his key is required, I am unable to open those doors. Is it a bug?

[Requin des bois]

Yeah, Steam version is full of bugs compared to the Switch one (stuck in enemies or totally out of battle area like during Forest Queen fight where I was sent miles away by one blow, and so on...).
If you are staying on the slab, and that you stay on it while the eye on the door is looking at you, yeah that's probably a bug. Maybe quit and load your save will fix.

[Solid Snake]

no its not a bug, i found you need to complete a puzzle in the sacred archives to get another key which is required to unlock all the prison doors.

[Requin des bois]

Weird, cannot remember such puzzle and I had no issue with the doors.