Wow, you got hub to test it, admire dedication hah, thank you. So basically it's working for you with aqara M3. It must be then, that aqara M3 hub is accepting signed data and m100 won't, m100 has been released later than m3. I won't be surprised if they will change it for m3 hub in future, they follow matter documentation like a bible, zero exceptions, or extra features at all ;(
Can you make changes to that 3 button switch: bf7faf9d5de46d95e0zofp
and to that 6 button switch:
bfb34a85404aa5e554g0lf
so I can test more switches and check if it still issue with all of them or only that single button.
If it won't work then I think the only way is to change firmware in tuya hub from signed to unsigned, but I can wait for it until future release, if you are willing to change it some day :d
edit: but if long press is accepted then others should work as well, when you change others switches then I will factory reset everything and set up my network again to check it finally.
Thank you.