Can't Insert the Three Fates into the Trialmaster's Tower

I've beaten the chaos trials with 75+ ultimatum's multiple times (at least 10 times). I finally have all three fates and tried to click on the door to insert the fates, but nothing happens. I can't insert anything. When I think about it, I have NEVER been able to insert anything into the Trialmaster door. Any ideas?

Reference screenshot: https://imgur.com/a/ApjNF0H

I have the same problem.
I inserted the 2 first: Cowardly and Victorious.
After that, I bought the Deadly but cannot insert it.
I click, but nothing happens.

It has just worked.
Instead of clicking in the hole where the keys are, I grabbed the Deadly key and clicked in the door, below the slot.
Then worked.