Cutting and pasting between Art Layers

When cutting and pasting between art layers on a single exposure , i.e. from the Underlay to Line Art level I notice that sometimes it works fine
but at other times it cuts the entire exposure and the frame / cel disappears from the timeline.
This seems fairly random and I can not figure out why it works sometimes and not others .
I have experimented with the cutter’s tool properties but still cant seem to replicate this behaviour at will.

Any ideas ?