I have a raspberry pi 3 using image ubuntu-core-16-armhf-rpi3-installer-20170329.img
It seems to be working pretty well, currently with this snap:
Name Version Rev Developer Notes
nextcloud 11.0.5snap2 3685 nextcloud -
I have read some different threads about other issues/releases … is there a newer one, will it update to nc12 or later itself ?