Verify the macOS system is configured to enforce time synchronization with the following command:
/usr/bin/osascript -l JavaScript << EOS $.NSUserDefaults.alloc.initWithSuiteName('com.apple.timed')\ .objectForKey('TMAutomaticTimeOnlyEnabled').js EOS
If the result is not "true", this is a finding.
Fix
Configure the macOS system to enforce time synchronization by installing the "com.apple.timed" configuration profile.