Popup toolbar error?

Hi, I upgraded to rhino8 and start to use it.

I tried to make my popup and I copy some iconesfrom sidebar to popup.
Most of them are no problems but one of them is always removed when restart rhino8.
Acctualy it is not removed but the icon and comand are removed.

I copy flow command to popuup and change command to ! _Flow _Pause S=_Yes P=_No.
I tried to chang a flow command in side bar as same as above and it is appeared when restart rhino8.
Only flow icon in popup is aslways removed.
It is appeard if I just copy flow to pop up (I did not change command like above).

The command does not have no problem in Rhino6.

Can you tell me the wrong point or is it error?