Keep cutting projects and will cut different depths during cut. Have already flattened the surface and the material is flat. Don’t know why but keeps messing up projects. Feeling very frustrated.
Neither do we - please post some photos of some of the carves showing your symptoms
Slight Z-variation typically seen on pocket floors => play/give in the the Z-assembly or pulleys/screw.
Sporadic plunges/greater variations => mechanical issues like lost steps etc.
Check the screws in the pulley for the Z axis. There have been many reports of them coming loose.