Why did my Orien smart lights stop working with my HomePod using the Matter protocol last week?

HomePod Mini updated to 18.0 (from 17.8 I believe).

Orien bulbs are:

Manufacturer: LK

Model ID: light.A001524

Hardware Version: unknown

Firmware Version: 3.07.05

8 bulbs using Matter to connect to HomeKit, all similar, suddenly went to “No Response” in the Home app on 9/13 (yeah, Friday the 13th) under HomePod version 17.8 I believe. Removed all devices from Home, removed them from iPad and iPhone General->Matter Accessories, reset their firmware with 6 power cycles, and attempted to re-add them via the Home app as well as their native app. Native app works fine. Home says they were added to Home but they immediately show up as “Updating” followed by “No response”. One other smart bulb manufacturer is in the “Home” which experienced the same problem initially but upon reset and re-add is functioning normally. HomePod Mini was then updated to 18.0, the above process repeated, with no change. No changes were made to the network.