@BadgerBadger: Yes, I do have the same problems with the Dahua IPC-HDW2431T-AS-S2 (Serial number 5MFC36PAG6H7205 - 7215 and 7217)
In 2020 I purchased 12 of them, connected to a Dahua NVR 5424 and now 4 camera's have stopped working.
1. Disconnected the cams from the NVR and...