Hey, you're right; I wonder when I lost that. Strange thing is that I still can access root folders through file manager (just checked), therefor I thought I was still rooted. But I can't su from a terminal, so you're absolutely rightYour Magisk (framework) shows N/A so it is not workíng/installed and you should not have root!
Please try to get root back (without restoring a TWRP backup!) and look again for "adb root".
So you can see the problems some of us have with Magisk > 20.4 and LOS > 17.1
--- UPDATE ---
this is weird: tried to reinstall Magisk V21.4 from TWRP, and that appeared to work but back at system: still no root. Ran the Magisk uninstaller from TWRP then installed old V20.3, rebooted. Installed Magisk Manager, checked Magisk status and root through Terminal >> I'm back to be rooted now. Next wanted to check the adb root option but found I lost the "Developer options". After I re-instated them had to realize that the adb root entry now is gone .
Back in Magisk Manager installed an update to V 8.0.7 (of the Manager app), then tried to update Magisk, but that didn't work at all: it jus downloaded the zip but nothing else although I had set the check at "direct install".
For me this isn't a problem really; Magisk V 20.3 seems to be working fine, and I hardly ever use adb root on that device. Still extremely weird. And apologies for my post above; I really should have checked properly before writing