Hello,
According to reviews the SONOFF devices work well but in 2 years this is the second SNZB-01 switch that no longer responds even after re-pairing.
I have already had the same problem with three SONOFF SNZB-02 sensors.
Here is the information I have :
I have one that I’ve disabled for the moment and that’s still connected 
:
Which Zigbee USB stick
Hello @prohand and thanks for your feedback.
I use the following dongle:
Model: ZBDongle-P
As for the Z2mqtt version, it’s the one integrated into Gladys and updates automatically.
Wireless connection: Zigbee3.0
Input: 5V-- 100mA Max FCCID: 2APN5ZBD-P
Str
I don’t know where to find the info. I’ve looked everywhere without success 
Thanks @prohand I had to search to find it and indeed, the version doesn’t seem to be up to date. I’ll take a look but I’ll still need help.
Sonoff has a website to update the firmware from a browser (Chrome or Edge 
)
I have Chrome.
Do I need to unplug the dongle to connect it to a computer?
What risks or precautions should I take?
I’m always afraid of messing everything up
I suggest you wait 24 hours; there is a zigbee2mqtt update in the Gladys release available today (if you installed this integration via Gladys). This could solve your problem.
For the update, you need to turn off zigbee2
Yes, first try updating Z2M to 2.4.0, and if you still have the problem, update the firmware version as indicated above 
I also have the same issue since the update and I have an SNZB - 02
At one point I got a message that mentioned version pre-01, I don’t remember. And also an issue with Aqara… the outlets seem OK.
I have the same as you: 2.4.0 for Z2M and the coordinator at 20210708 (i.e., 2021). If I understand correctly, you need to take the dongle and update it via our PC to flash it? What’s the procedure?
To flash, you can try via the browser as suggested by @cicoub13 if you have a ZBDongle-P or a ZBDongle-E:
