I think the issue is with a Mac update or a conflict - I worked on updates now and have not used Ventura on our iMac for Affinity - and now it seems to work OK-
The 12.7 Monterey OS update is a bit more stable and unbloated - I have Publisher also - And now I cannot change the Colour of the Bleed (from the default 'Mauve' shade which is not suitable for easy positioning with bled images, to our preferred Bright Red bleed) - I tried the document 'set up' but it simply does not Change at all
So? It's not a big deal generally, but we publish a lot of mags so for us it is...