Can't scroll thru certain clips frame-by-frame using the arrows in bottom rt of kbd

Hi,

Running Mac mini with M2 Pro chip, Sonoma 14.5.

I used to be able to scroll thru clips frame by frame using the kbd arrows in bottom right while listening to find the exact beginning or end of some audio.

Now, most of the time, I can't hear the audio, dead silent... unless I tab out of FCP to anything and tab back in. Then I can hear the audio until I click in a screen and then I have to tab out/tab in.

How bizarre.

It began a few upgrades of Sonoma back.

Any ideas what to do?

best,

royks