This is normal.
I think the only thing you can do with ADB and TWRP is putting TWRP into ADB sideload mode (Advanced - ADB Sideload - Swipe to Start Sideload), then “unauthorized” will change to “sideload” (if you check again), and you can sideload stuff via ADB.
I see. Not sure this is as intended though (at least not as I remember it?). I got your tip from the other thread about fastboot booting TWRP from RAM and that works, but I just get a TWRP logo screen. I have no buttons or options on the phone.
Now it appears as “recovery” from adb devices instead, if I try to do adb backup it asks me to “Now unlock your device and confirm the backup operation…” but the screen remains on the TWRP logo and nothing else.
Ok, you got me searching the web, and my knowledge was old.
While not supporting the full ADB set of commands, TWRP from version 3.1 on supports adb backup and adb restore operations …
This is new to me too, good that you learn something out of this as well. I’m trying and will read up myself, but my issue right now is that I cannot find a way to decrypt (or unlock) my device while in this TWRP-screen. adb shell is working so something is running at least!
And so on when I try to access any folder mounted from the MMC. I don’t expect I’ll get much data out of this even if I had the chance. Opening a support ticket with Fairphone, this phone is about 16 months old.