It looks like you're using a Discrete (Blue Pill) Minute([Timeextract]) on Columns,
so you've got a number of (distinct) Headers instead of a Continuous X-Axis.
Try making your Minute([Timeextract]) a Continuous one (Green Pill).
and see if you could then format the Axis Tick Marks as you want.
I did not want to make it continuous. I changed the orientation and I added the hour tab before it. The hour tab shows but I hide the minute tab. Just a way around for now.