Help. Rapid move missed target by 2 inches

You are cutting a slot just as narrow as the tool:

That will work until the time it doesn’t work.

Assuming the machine is in good condition, all wiring in good condition and connectors secure, pulley set screws are in place and secure, belts well-tensioned, eccentric nuts adjusted so that the V wheels are correctly aligned on the rails, and nothing mechanically interfering, then what happens is high tooling engagement will result in the machine being pulled into the cut.

Where possible avoid slotting and add geometry and cut as a pocket

and/or

and consider leaving a roughing clearance and taking a finishing pass.