AMS 2 Pro - 4th spool at the right doesn't rotate in drying mode

Bambu Lab AMS AMS 2 Pro
1

Anyone else here face this issue?

I had a camera setup a while ago, I can only see the first 3 spools from left rotates during the drying process but the 4th one isn’t moving at all.

There is nothing obstructing it from spinning.

The motor works as it can read the filament, feed and unfeeding.

2

@kip were you ever able to find a solution to this? I came across your post as I’ve also noticed that the 1st slot on my AMS 2 Pro does not rotate during the drying cycle, but works fine when printing.
Mine is also clean of debris, and there is no obstruction.