Thanks for all the advice in these posts.
I’ve:
- reserved an ip address for the roon core and all the remotes
- made sure randomised MAC address setting was turned off on the android devices (already was off for 2 of the 3 devices)
- turned off battery optimisation on the android devices
Since doing that it hasn’t had any connection issues and only got stuck on the roon loading screen once, so does seem to be more stable.