Playback not starting

Since the latest update, I can’t start playback in WL9.0.25.
Pressing play results in WL to try to play…freezing it for about 5 seconds, then it gives up at the same playhead location (it doesn’t move on at all). The first tenth of a second gets played back - can be seen in the analyzer displays. They freeze too after that and stay that way.
I always have to restart WV9 after a system start once, for the playback to work correctly.
What could be the culprit to such an behavior?

Should not be the case, but maybe an interaction with a watch folder instance. Try to quit this instance, if any.

Apart that, is this ok:
File > Preferences > VST Audio Connections

I saw that not only in last version Wavelab is very very slow when a playback is required before to start.