I have exactly the problem that everything seems normal at first when feeding via slot 1. As soon as the filament arrives at the 4:1 internal hub, it is no longer fed in and is blocked. I have already checked the tubes and foreign objects in the internal hub. If I feed filament manually and turn the motor in the internal hub slightly, the filament is drawn in without any problems. Presumably the feed motor in the internal hub does not start when I feed filament via slot 1. What could be the reason for this?
@Bratzer Have you been able to find a solution to your problem in the meantime?
Update: I have now replaced the AMS First Stage Feeder from slot 1 with the one from slot 2 to rule out a defect.
I have also removed the internal AMS hub unit again and could not find any visible defects or foreign bodies left behind. There is probably a defect in the Hall sensor, which currently no longer recognizes that filament is being loaded and therefore the motor does not start. I have now opened a ticket.