Extra simulacrum waves?

Report ID 4,077,506,202

So I left a simulacrum (+4) after finishing it to deposit my swag and get another one out. Noticed my hideout latency was 76ms, which is odd, so went back in to check my latency inside (10ms inside).

I found the start guy offering me wave 16/15.

I checked if it activates, and it doesn't...but this is quite bizarre.

The secret 16th wave is where all mobs and bosses are resurrected and come chasing you down to get their loot back.