My passenger seat won't slide forward when using the easy access lever (the one on the outside of the seat).

The seat back folds down just fine, but it doesn't go forward after the lever is engaged. However, I can slide the seat forward and backward using the adjuster under the seat.

So I have a workaround by pushing the easy access lever and pulling the under seat adjuster - but it's frustrating that the lever isn't doing what it should.

I can't see anything obviously wrong with the seat or the seat rails.

Any thoughts on what the problem might be and how to fix it?