occasionally seems like Mouse button presses are up/down immediately, use Shift key forces the state

When I use Big Sur as the host and guest (version 11.4) with Eclipse (Version: 2021-03 (4.19.0)) occasionally the mouse requires holding the "Shift" key to enable the action to persist. When in this weird state, not holding the Shift key will flash the menu. It's as if a double mouse event happens (up/down of the button press).

Anyone else encounter the mouse double press symptom?
know the workaround?

presently I simply restart the guest. Which, either I am using Parallels more and it was always unstable, or the latest version is considerable less stable
Version 16.5.0 (49183). The present stability has me thinking of investigating using Docker/X-windows instead.