Anycubic - ACE Pro is reversing the filament out when attempting to feed

Issue

After disassembling the buffer on the ACE Pro connected to your Kobra S1 Combo TL5210 or Kobra 3 Combo TL5200 printer for cleaning, when feeding new filament into your ACE Pro, it pulls it in briefly, and then reverses it out.

Cause

The magnets on the spring-loaded buffer tubes are oriented down instead of up. See this thread.

Fix

Remove the buffer cover and rotate the tubes so the magnet is facing up. See here for details.