Bluetooth microphone not detected

[wrzomar]

I can confirm, that all my bluetooth audio devices on Manjaro ARM have only A2DP profile, which have only stereo output. On default "Debian" (in January, I think) bluetooth audio was barely working, switching to HSP/HFP profile was either crashing bluetooth or disconnecting, restarting bluetooth wasn't working either (only a bluetooth mouse was working back then). Also, my bluetooth speakers worked then in A2DP mode only with single speaker, pairing two speakers together (for stereo output) also was crashing bluetooth. I've kept original eMMC module with "Debian", but I cannot test bluetooth with it, because it was the last thing that stopped working and it was the main reason to ditch "Debian" on PBP.
But on the other hand, it wouldn't be the first time something isn't fully working on Manjaro, e.g. HDMI audio (or whole HDMI in case of mainline kernel), send SMS in KDE Connect, adding projects in BOINC Manager.
Do not let go. You need to test your headset with other distros and something else than PBP, check versions of packages related to bluetooth audio (from firmware to pulseaudio), use ArchLinux Wiki if you're not familiar with bluetooth on Linux.
Do not let go, because the only working microphone on PBP is the left built-in microphone. I don't believe in dual jack on this thing, the microphone in my wired headset was never working on PBP. The bluetooth headsets would be the only solution to recording audio on PBP with something better than the built-in microphone. Try to avoid 2,4GHz WiFi, use 5GHz WiFi or Ethernet to avoid interference.