Jim Bailey wrote:

....
Well, dry biscuits in the slots have about a 32nd clearance, which of course
translates to the same vertical movement when the joint is together. I'd
hoped for a much more snug fit than that. You can also slide the 2 joined
edges laterally about an inch either way - but that's not a problem - you're
lining up on your original biscuit marks anyway - but the vertical movement
bugs me a bit.
....

Sounds like undersized biscuits or slightly oversize cutter--is there a
burr on the edge of the cutter by any chance?

The slot w/ my Ryobi is snug enough that it takes a really firm tug to
pull a dry one out of the slot directly normal to the face.

Horizontal alignment is, of course there to allow some movement, but the
vertical slack shouldn't be anyways near 1/32"...