After having had several problems with the latest versions of magisk on this device, I have successfully tested the root by flashing via recovery of addonsu, the official root method of lineageos. By doing this in the developer menu you will be able to activate the root and manage permissions. Attached both the root and the unroot. I haven't tested the unroot but it should work too. If the rom developer wants, he can attach this alternative root method on the front page.