Client check passed/Inactive

my question is regarding ‘Client check passed/Inactive’.
I was thinking these are machines which were previously responding to SCCM but are currently switched off, unplugged, offline etc. and not sending any info from last 7 days.
What I don’t understand is the ‘Client check passed/Inactive’ column lot of machines are online, pinging, the SCCM client appears to be functioning correctly from what I can see yet we are still seeing these 24 machines.

I repaired 1 online machine and it came out with return code 0 but no further action.