So I accidentally clicked "Don't show this again" on the dialog box that lets me choose which audio device to use when I plug in my headphones. Now it just won't swap at all, unless I restart/boot up my laptop with the headphones plugged in.
Even then, if I unplug them, then connect them again, it won't detect them.
I have uninstalled the RealTek Audio device in the Device Manager, installed a different driver, reverted back again, disabled and enabled it again, all to no avail.