Stair flights substantially undercounted

I need to build up to the ability to climb 50 flights of stairs without a substantial rest. I’m far from that right now. So I started tonight by going upstairs and downstairs in my house 5 times without a rest, and then a short while later another 5 times. Earlier in the day I had normally used the stairs both up and down four other times. So I would expect 14 flights to be shown for the day. I checked it and it says I’ve done only six.

And then some googling revealed that this undercounting issue has existed for over ten years.

C’mon, Apple. You can do better.