The issue appears be resolved. The fix was either a server side change, AppleOS27 or both.

I confirm this behavior continues with all devices updated to 27.2 RC. Vision Pro even states that I'm out of requests even though I just put my Vision Pro on for the first time today and made a single Siri request. Yesterday I enabled the camera summaries in HomeKit after installing 27.2 RC to see if the behavior corrected but it still persists. HomeKit camera PCC requests should be separate from actual Siri AI use since its a paid feature.

Turning summaries off seems to help.

I think I found part of the culprit - I woke up today with Siri AI not working - not even the light control works. Nothing of mine should have been hitting PCC so I checked the Apple TV that is the home hub that uses PCC for video clips: What it sends: mediaanalysisd on the TV analyses HomeKit camera clips and routes each one to "Pro". The number of clips routed per hour matches the TV's completed PCC requests hour for hour (43, 63, 70, 43, 13, 15, 25 and 29 from 04:00 to 11:00). Why every clip goes: The routing threshold is THR=0.0000, so everything goes to the cloud. 4,213 of 4,291 routed clips had no person, pet, vehicle or package, all with the same score of 0.2115. That looks like wind-triggered motion. Volume: 694 clips in the last 24 h, against a daily limit its daemon was told about (rate limit discovered: count=500, duration=86400). Oct 2 had 1,442. Today's 351 requests since 03:00 all ended in errors 32080/32081. Its been a windy day so there are more than normal recording on an average day but this feature on Apple TV - is it intended to block PCC for my entire iCloud account for video events? Is this intentional or a bug? Should I be disabling summarized videos completely to avoid this?