Xiaomi aqara firmware and connection issue

I’ve invested in a couple of Xiaomi aqara contact sensors and a motion sensor. Pretty impressed with them, especially given the price. I’m using the bspranger handlers for them which are great.

I’m having an issue with one of the contact sensors - it keeps losing connection and I need to remove it and re-add it.

I’ve looked at posts and comments regarding WiFi/ZigBee interfere. There is another contact sensor a metre or so away which is having no issues at all, though, so I assume it isn’t that.

The devices are in an out building and using a couple of repeaters along the way - 1 Smartthings outlet and 1 hive outlet.

Any thoughts? Could it be a difference in firmware perhaps? Would I need to Xiaomi hub to update the firmware on these? Can I find the firmware versions through the ide?

Thanks in advance.

Xiaomi devices can’t use repeaters