Correcting a transcript

Hello fellow Prem Pro users,

I'm an occasional editor & so have just started using the transcript/captions feature. I've initiated transcripts for some source clips I've already imported & have then gone through the first clip's transcript & corrected it as needed. I did that by being able to hear the source clip's audio & watching the cursor follow that audio in the transcripted text & then hit the space bar to stop the audio & then double click into the transcript, make the correction, click out of the text-highlighted box & move on through the transcript. So far so good.

After completing corrections for my first clip & doing a couple of other edit things, I've come back into the 'captions & graphics' workspace to work my way through checking the transcript of next source clip & for some unknown reason, I can no longer use the space bar to stop the audio as I watch the cursor move through the source clip's transcript. This means I need to hit the tab for the source clip's file name in the source monitor (which then shows the source clip) to then be able to hit my space bar & stop the clip running & then click on the text tab to return to the script. This is a much more clumsy way to make corrections.

What am I not doing right this time around??!

Many thanks for any helpful insights.