@Josh-3D is correct, I had the exct same issue.
I explained the testing I had performed in detail and how TPU had a really poor quality when printed using a hardened steel nozzle on the A series (both A1 and A1 mini).
If I swapped back to the stainless steel nozzle, everything worked perfectly.
I was going to perform additional tests, but, I haven’t yet. I may do some tomorrow (it is 11 pm here) as I would like to know if anything has changed since.
I still have both nozzle types and lots of lovely TPU to play with.
I only have the A1 mini now (the recall took the A1 and P1S combos (many) replaced it).
In my first tests, the A1 and A1 mini had identical outcomes. The same should be true now.
BTW, speed did not affect the outcome. Nor did High Flow vs traditional TPU. The filament supplier also did not matter.