Rancor and Game Afoot - bugged perk interaction.
PC, probably affects all platforms.
During a match against a streamer, I unknowingly triggered a bugged perk interaction.
There were two survivors left alive, a Cheryl and a Steve. I chased Cheryl, downed her, then went to get the Steve. He got rancor proc'd with Game Afoot, but I went back to the Cheryl who was still downed and hooked her. I was going to go back to the Steve and rancor mori him, but the Cheryl 4%'d so I went back to her again.
Cheryl was swapped back to obsession by Game Afoot after I downed her again, but when I went back to Steve after putting her back on the hook, somehow he was still moriable.
I highly doubt this was an intended thing and I will avoid using these perks in combo due to this issue until a possible fix is issued.
Edit: Forgot to mention this took place during Endgame - gates weren't opened yet as I had No Way Out.