You must flash the last stock ROM, later flash the TWRP 3.3.1 via odin from Ashyx or the provided by vlw on Android File Host, next flash Lineage 17.1 and test again if something works.My device is A300FU. What I wonder is whether there are problems like wifi not working, or echo in calls, as some fresh custom roms do. I am running lineage 16 currently, and for instance the menu button doesn't work.