Keywords from DPL 5.0.1 not visible in DPL 5.0.2

[platypus (Canon & Mac (Intel and M1))]

This might be a related issue:

Rating/IPTC from Lightroom read inconsistently in PL5 Windows

I refreshed several times to no avail. The “keep metadata synchronized” was not checked. Checking that fixed the problem, although I don’t understand how two folders worked OK and two didn’t.

Is there an implementation difference between manually reading/writing metadata and synchronisation?