Ilkka, it seems you've got a stable configuration there that works consistently each time you need it.
It was the lack of consistent behaviour that forced me to abandon Snapbridge,
A friend of mine who is pro photographer just bought the latest iPad Air, and he found that he could transfer the NEF files very quickly from his Z6 connected with iPad Air via USB-C cable. .
Hi Akira, I must say that even with hardware a few years older than the Z line (D500) I never had a problem getting a connection with my Windows laptop using a USB cable. That worked fine for both file transfers (not a priority for me) and to a degree, for remote control using the Digi Cam program.
Sadly because of the need to use Nikons proprietary USB connector, the limited cable length again restricted its use.
Edit - I now realise this was wrong
But what I really wanted was a reliable
wireless connection - ideally with my tablet, but at a pinch the laptop.