Does it need updating ? print profile needs to be set up for multi colour prints
go into preview tab in bambu studio and check here
for specific changes at specific layers
you may also need to check you have the colours set correctly (by type) here
where you can add or delete the number of colours ,note not all filament types will print the same object using the ams
AMS lite | Bambu Lab Wiki
printed on my A1 with ams lite yesterday
one other thing to add (a1 mini) if you plug it in the wrong socket the printer will see the ams, but doesnt acknowledge it and gives external spool empty error instead , i havent looked at with the a1 but worth checking