So for some reason, my phone decided to install the new OTA update of OxygenOS.
I wanted to reinstall Magisk after flashing TWRP back but when I did so, got stuck in a bootloop.
I managed to get my phone back by re-flashing OnePlus5Oxygen_23_OTA_052_all_1910082005_d4a454d1d3e44852.zip but...