Thanks for the reply John. Unfortunately the link to enable auto-updates is not there for ACF Pro, while it is there for almost all other plugins. So I can’t turn it on to see what happens.
I’ve contacted the developer through a ticket, so we’ll see what they say. If ACF Pro indeed doesn’t support WordPress’ auto-updating mechanism then it would be great to see that added. Could save a lot of time and hassle.
Thank you for the reply John. It got me thinking, and it turns out the block editor comments were just leftovers from testing the new editor experience before switching to the old and copying some content over to other fields. I assumed these comments were incorrectly being added to all WYSIWYG fields, but it was just me.
Good to know, false alarm, topic solved.
