I have no idea about LOS17, not yet installed on my phone, too early product for me. I also don’t use Magisk, no idea what to do for that case.
But I read that Lineage does not provide anymore the root addon package with LOS17.1 (“As a byproduct of this, our usual provided AddonSU zip to enable root access for the user is no longer feasible.”).
The only thing I can tell you is that if you flash this org.fdroid.fdroid.ota_1001050,
- it should install F-Droid app (make sure it was not already installed before !).
- And then installed f-droid apps will automatically update when needed.
As a result, IMO, if that does not work anymore, it could be a root issue and you may check with Magisk support guys.
Let us know your findings.