Copy/ Paste Issue

Say you have 2 identical rigs, and a certain peg has an expression in position x. Rig A and rig B has this expression in this peg, but the expression is slightly different.

When I copy a pose from rig B to rig A CTRL+C, CTRL+V it works as expected, unless I paste it at frame 1. If I paste at frame 1 then ToonBoom will paste the expressions from rig B on rig A replacing them.

It gets worse when using CTRL+B (Paste Special, using the setting in the attached file) because it will always replace the expressions.

We have just upgraded to Harmony 20, but this issue was present in older versions also.