I found some 0x0000 UUIDs in some devices

[Paul]

What is the point to have 16 bit 0 UUIDs or 128 bit 0 UUIDs in the accessories?

[MartinBL]

Can you post a screenshot of the sniffer log? I can't see any reason for going for a UUID with all zeros. But I guess an all zero ID is just as unique as any other random number.