For some reason my Volumio 3 on Pi3b is not showing version information in tje system page of settings. I think this is why it can find any uodate and says it is the lastest version.
Is there another way I can check the version?
It works fine though. No issues other than the missing version.
How is the version info captured by the web ui? Is there a file or config flag that show it?
‘cat /etc/os-release’
Could it be you played around and did an ‘apt upgrade’ by mistake?
Oh man! i don’t remember but this is what I get with cat /etc/os-release:
PRETTY_NAME=“Raspbian GNU/Linux 10 (buster)”
NAME=“Raspbian GNU/Linux”
VERSION_ID=“10”
VERSION=“10 (buster)”
VERSION_CODENAME=buster
ID=raspbian
ID_LIKE=debian
HOME_URL=“http://www.raspbian.org/”
SUPPORT_URL=“RaspbianForums - Raspbian”
BUG_REPORT_URL=“RaspbianBugs - Raspbian”
If this is due to apt upgrade, is there a way to fix? (hopefully without reinstalling Volumio) 
There is no way to fix it, just reinstall the lot.
Don’t do apt upgrade, it kills your setup as Volumio has its own (though Rasbian-based) distro.