Green line during playback

Dorico Pro 4.1 is showing a green line during playback which doesn’t always keep up with the music.
I havie tried resetting the sample rate but the cursor line is still a thick green line.
I think this has only been happening since updating from the most recent maintenance update to Dorico 4.1
Any help would be greatly appreciated

How far behind the beat is it?

You could try lowering the buffer size for your audio device in Edit > Device Setup, in your device’s control panel interface.