I don't know if this helps. When i was using Lineage 14 with selinux enforcing, i also ran into this problem. Developer also say that the ROM was not rooted but can be rooted if the user wants to root. Problem was Banking apps keeps rejecting. Finally, I downloaded and flashed "SUcleanup.zip." After that, the Banking app worked and stopped reporting that it detected "root." You can try searching for these files and try flashing them to see if it works for you. It seems that although Lineage roms does not come automatically rooted , it has some of the su binaries files and folders to make it helpful for someone who wants to root with chainfire's rooting method.
@tarkzim, I really, really like your builds, but because of one problem, I can’t use them. This is a problem with GPS. On LOS14.1 from @ nijel8, my phone receives a lot of satellites. But on your new build and the previous ones that I tried it takes 3-5 satellites, no more. And the connection with the satellites is broken 5 times per minute. On other people's android 10 builds GPS works a little worse than on LOS14.1, but it works ... Please check your GPS operation. My device: Mi Max 3/32 hydrogen. Sorry for my English.
see screenshots below:
* Your warranty is now void. * * We are not responsible for bricked devices, dead SD cards, * thermonuclear war, or you getting fired because the alarm app failed. Please * do some research if you have any concerns about features included in this ROM * before flashing it! YOU are choosing to make these modifications, and if * you point the finger at us for messing up your device, we will laugh at you. * */