Greatest Subject Tracking (except...)

So here I was photographing a track meet at a local college.  And I brought the new Sony A6400 which is said to track subjects as well as the A9 with Firmware v5 (yet costs thousands less!).

I wrote up my findings and submitted a whole string of sample sequences for the latest issue of Cameracraft magazine.  One of the sequences had the camera successfully track a pole vaulter even though the athlete was partially obscured for a few shots (some samples from that sequence appear above).  This prompted David Kilpatrick, the magazine's editor, to proclaim, "[T]he sequence is very impressive as I’m not sure any camera I use now (A6500, A7RIII, Olympus) would hold focus on the subject in these circumstances."

But, I found a problem.  Which I'll relate to you in a bit.