Hello @ActionAndi,
in the right upper corner there are three vertical dots which open menu by clicking on it. There you choose Monitor view. Default view is Output Table and as some nodes (Table Row To Variable Loop Start included) don’t have it then you see this message. Change it to Variables view to see iteration numbers. Check picture for reference.
(The reason why it was working for you out of box with previous versions is cause Variables view used to be default view and that was changed recently to Output Table view.)
Br,
Ivan