The problem for me is mainly that we upgraded our server 2012 to 2019 but did not raise the domain functional level to 2016. The new LAPS need to be at 2016 domain functional level.
Likewise, the event logs of the DC are not helpful. LAPS is now working but the events still show a succession of 10003, 10024, and 10004 events.
The key to solving our LAPS problem, which I thought I read from here, is to check the events in the client computers instead. The LAPS event in the client computers shows specific errors, like the DC must be at 2016 domain functional level.
Solution: check the LAPS event log of the client computer, not the DC