When tracing tissues on MRI sometimes the segment goes past the desired layer onto the next level

I am tracing muscle and leg tissue with a 10 mm separation between each layer. Most of the time I have no issue of tracing the tissues and moving on to the next layer. Sometimes when I draw on one layer it continues to go to the next layer and doesn’t allowing for a new segment on that new layer. Any ideas of what I can change or do to not have this happen. In this example I created a midpoint and made 5 layers above and worked my way back to the midpoint. I had an Issue on the first and second layers after the midpoint but not the other 3.

Windows 11 Pro
version 22H2
build 22621.2428
3D Slicer version 5.4.0

If you cannot paint independently on each slice of the background volume then most likely the geometry (origin, spacing, axis directions) of the segmentation is not the same as the background volume’s geometry. You can use the “Specify geometry” button to resample the segmentation to match the source volume’s geometry.

Note that it is very unusal and probably unnecessary to create a new segment for each slice. If you use the same segment for the same structure on different slices then that makes things much simpler. You can also create a full 3D segmentation from a couple of slices using the “Fill between slices” effect.