Form 2 not printing parts of supports

This has been an occasional problem but has been more frequent the last couple of weeks.

The initial layers go down and the supports begin to form but part way some of the layers don’t print only to begin again when the layers get to the model itself. There’s also a thin layer applied to the platform at the start of the process. See pic below.,

The important part of the model seems to be fine it’s just those initial layers which are not forming/warping.

Both the printer and the Pre Form software are up to date. The mirrors were cleaned recently and a new tray started. The cartridge is fresh this week.

My only thought is that the support settings need some adjusting. Any suggestions would be most welcome. Thanks.