KMail mail context menu partly unaccessable

Right-click on a mail in the list and get the contextmenu:


When moving the cursor downward over the menu to reach the item wanted, all goes well until reaching the item Move Message To … Then the menu vanishes (as if one clicked outside it)

See this on two different systems (with two different users).
More people having this?

Edit: One can move the cursor outside the menu to the bottom. From there the last item can be reached, but going upwards to Copy Message to … lets it vanish. Thus it seems to be restricted to those two items.

Here it is “Mark Message” and same behaviour in main menue “Message”, too.

I found a bit different.
It is again the Move and Copy ones. When coming from below, the Mark is OK and the Move stays sometimes and sometimes not (??). Copy always removes the menu.

A bit of a mess?