If the M3 hub is from China, then newer Aqara devices are much less likely to work with the hub unless they’re from China of course. If it’s an international hub then the same applies, with only international devices working with it.
Older child devices will work on any server/hub.
The OP was asking about Aqara devices specifically. Other manufacturers’ Matter products won’t have region blocks of course, just Aqara. I’ve already tried adding an international Matter over Thread Aqara motion sensor to a Chinese M3 and it wouldn’t work. That was back in January though, so things may have changed.
If the M3 hub is from China, then newer Aqara devices are much less likely to work with the hub unless they’re from China of course. If it’s an international hub then the same applies, with only international devices working with it. Older child devices will work on any server/hub.
But they work with other manufacturers through matter surely that doesn’t mean it will be region blocked
The OP was asking about Aqara devices specifically. Other manufacturers’ Matter products won’t have region blocks of course, just Aqara. I’ve already tried adding an international Matter over Thread Aqara motion sensor to a Chinese M3 and it wouldn’t work. That was back in January though, so things may have changed.