Also note: In the wild, in addition to channel 25, I have seen reports of Xiaomi Gateways operating on ZigBee channel 20 and channel 11 (here and here.)
Since both Xiaomi and Aqara branded Zigbee devices are supposed to be compatible with either Xiaomi or Aqara branded Gateways, I have to conclude the end devices should be capable of operating on at least a number of different channels.
There was quite a bit of discussion early on in the Xiaomi Devices - are they pairing / staying connected for you thread (probably a better choice of thread for this discussion, BTW), and user @NoWon reported difficulties with Xiaomi devices on channel 25 (not sure if that was just older Xiaomi or a mix including Aqara devices), and then seemed to have more success with channel 20.
I myself went from using channel 26 to channel 20, subsequently experiencing few issues, and have stuck with that, though I will say that my Aqara Wireless Smart Switches can be a pain to pair (I have been moving them back and forth between my Hubitat and SmartThings hubs for testing and working on DTH/driver improvements).
I haven't tried changing to channel 25 though, so I can't say whether that would help with things. I do know that when my Xiaomi/Aqara devices pair via one of my XBees, it seems to be a lot easier/quicker in general.
