Master sync issues

I’m having a problem since I installed the last update, but I don’t think it’s really connected to the update.

In short, the master sync doesn’t change from the deck stopping to the next deck playing. I’ve not changed any settings that I know of and I’ve searched pretty thoroughly for an answer, but have found nothing. This is causing problems when cueing other songs on the other two decks.

Any help greatly received.

Mac OS, M1 chip, Denon x1800, serato timecode vinyl and 2 x LC6000’s.