Okay I’ll attempt to explain it better.
With a sequence playing press record so that you have a red stationary cursor and the screen stops scrolling, (but the sequence is still running).
Now use your MIDI keyboard to drop a note wherever want in your sequence. When I try this I hear the note play as I trigger it on my OPZ and the step jump takes me to the next correct step, but… no note is actually entered into the sequence, despite being in record.
It seems that with a MIDI keyboard I can only enter notes if either the sequencer isn’t playing, or I’m in live record mode, where you play in time with your sequence.
With the original Tracker using the inbuilt keyboard I can press record on a playing sequence and just drop notes into the sequence wherever I like, by scrolling to the step I want and pressing whatever key I want to use.
I guess this must be a bug. I never used a MIDI keyboard with my original Tracker, but I wonder if the behaviour will be the same with that.