I have 8 Sonoff T1 installed, 3 of them 3 Gang, 3 of them 2 Gang and two 1 Gang. It seems that most of them randomly "resets". Emits a single beep, pause and then two beeps. The light flashing and then back online again in a minute or two. This is very disturbing if it happens to one of the three switches close to my bedroom in the early hours of the morning! They all have the latest firmware. Why does this happen? Can I stop it from happening? It seems like especially the one does this quite often (sometimes more than once a day) while some of the others never do it (that I've been around them to notice). Any thoughts/suggestions?
Mine all starts with 10006, so not the same problem you seem to be having. All three the T1 3C is in the 10006 range and all three resets with 3.3.0 (less often than it did with 3.1.0).
Has anyone tried adding their devices to a "Guest" network on their router? Make sure nothing else connects to the guest network, only the Sonoff devices and then use your normal network for all your other devices.
My Mate did this and his switches hasn't beeped since... i am sceptical though and don't have the time at the moment to test for myself... Feedback would be greatly appreciated.