I followed each and every step, and realised a little too late that my laptop is a HP ProBook x360 11 G1 -and not a G5. The G1 requires the ability to de-solder the built in charging port.

On step 6, I noticed there were 6 screws holding the battery in, not 4.
Then on step 9, I noticed that the charging port is actually soldered to the motherboard and there is no visible cable attaching it to the board which can be unhooked.