The TDZ leagues total standing for Cat.A shows 5 events for me, but at my personal zwiftpower page are shown 6 events in Group A ... which is correct.

Which one is missing?
Is there anything that I (or you) can do that all 6 done are counted at Cat.A?

Many thanks!
BR, pat

PS: if I do the stage 5 at the makeup days again, and this time at group A, would this be counted for total results in Group A ...?
Or will it count still at group B ... as this was my first attempt?

It may just need a manual update so look again tomorrow.
If you did Stage 5 (A) I'd expect that to go towards your total results for Cat A.