Just had to cancel a print halfway through due to the Filament Track switch blocking the second/ aux in/ outlet for some reason. Cancelled the Print, undloaded the Main Nozzle Filament and now it seems to be working again.
It would’ve been just nice if both nozzles would be loaded at the start of the print once, instead of the aux nozzle to be loaded mid print for the first time when needed, so problems like these don’t occur mid print and potentially ruin a whole print.