It constantly disconnected with a rather scary noise in my car stereo’s speakers.
After a few-days’ stay at my favorite shop’s repair workshop, the verdict was rendered; the BT module replaced, and the software patched (Which patch? No idea).
So it seems that my issue was not a general problem for the Z1 Compact line. However, if you have a similar issue, or any other issue, your experience is of interest to me.
That’s what the comment section is for 🙂