slot a

Hello, my goal is to flash TWRP onto both Slot A and Slot B. main slot 338 login I've flashed TWRP into Slot A, while Slot B is flashed with LineageOS recovery, currently I'm pretty sure I then flashed the OS/ROM with TWRP into Slot A but afterward I had a warning that read, "No OS Installed" - I thought it was a fluke, I rebooted System and it went back to TWRP