When I try to display prisoners in the Summit, they always disappear, seemingly despawning and returning to the collection. Not sure if this is an intended mechanic or a bug, but either way, I'd be grateful for clarification. For clarity, the prisoner's opinion of me doesn't seem to matter, and neither does whether they're assigned to a facility or not. I am playing the web version of the game on PC.
I think it's related to the Cuddle Lounge. Prisoners assigned to it get displayed in its cages. Even if they were locked in other furniture by the player. This can happen while the player is looking, resulting in the apparent despawning of the prisoner from its player-assigned place.