Cannot enable Apple Intelligence summaries for a second HomeKit camera

Updated my HomeKit setup to version 27.

I have that 6tb iCloud+ plan, which should let me enable Apple Intelligence summaries for 2 cameras. It even says it supports 2 cameras right in the Home app. However, I can only enable summaries for one. When I try to enable it for a second one, the slider just snaps back.

All the cameras are native HKSV devices from Aqara (no bridges involved). Already made sure everything is properly update, restarted all the HomePods and AppleTVs, even removed and re-added some HomePods and the cameras themselves - no dice. Anything else I can try?