This might be the way it's supposed to work: there will be 4 click stops to place the chain on one of 3 chainrings on the front. Click stops 2 and 3 are both for the middle chainring. If the chain is on the biggest cog, you need click stop 2 in the front for middle ring. If the chain is on the smallest cog in back, you need click stop 3 in front.

Or something like that. The extra click stops up front is called the "trim" and is needed to deal with the chain angles in some gear combinations.