: LineageOS 14.1 (Android 7.1.2) remains the "gold standard" for this specific hardware . It provides a much cleaner experience than the stock Android 5.1 Lollipop, though it is now significantly dated for modern apps
If you need help gathering the exact files for this project, let me know: samsung galaxy tab a6 smt280 custom rom updated
A: Unlikely. Without SafetyNet passing (impossible on an unlocked bootloader with this old hardware), banking apps will refuse to run. Use your phone for payments. : LineageOS 14
In TWRP, tap and select: Dalvik/ART Cache, System, Data, Cache . Swipe to wipe. tap and select: Dalvik/ART Cache