Summary
Flash ih8sn provided by althafvly or your maintainer(s) via Lineage Recovery, and banking apps will work correctly.
Explanation
When you use banking apps on LineageOS without root, they may show the misleading error message that your device is rooted. Banking apps actually check SafetyNet or Play Integrity, both of which are used to verify device integrity.
After flashing ih8sn, LineageOS will pass those two tests, banking apps won’t complain any more, and Netflix will be available on Google Play. You can install YASNAC and Play Integrity API Checker to check. LineageOS will pass Basic integrity and CTS profile match on the former, MEET_DEVICE_INTEGRITY and MEET_BASIC_INTEGRITY on the latter.
This tutorial was tested on Mi 11 LE (lisa) and Mi 9 SE (grus) on LineageOS 20.
Fun fact: ih8sn means I hate SafetyNet.