macOS and the continuing saga of softwareupdate (software update) being “frozen” or not working, no updates listed
There is a well-known issue with macOS in which a Mac does not show available software updates. This has been occurring since the time of macOS Big Sur - aka “macOS ‘(this one) goes to’ 11”
Investigating further
If you look at the running processes, you may see an existing softwareudpated process listed, which might have been active for some time.
Manually launching Software Update (in the GUI) or using the softwareudpate command, will simply sit without returning anything about available updates.
Remediation
To get past this, I have found the following helpful and the steps do not require a reboot:
Run the following via the Terminal (or remotely via ssh):
sudo /bin/launchctl disable system/com.apple.softwareupdated
Then wait several seconds, and run:
sudo /bin/launchctl enable system/com.apple.softwareupdated
Wait several more seconds. Note, the following should be (technically speaking) redundant and unnecessary, but think of it as one more “kick” to help get things working again:
sudo /bin/launchctl kickstart -k system/com.apple.softwareupdated
And - hopefully - you’ll find the problem resolved, as I have so far.