UltraVNC

I'm still having this problematic issue in Windows 10 which ruins my productivity with UltraVNC.

Is it possible to add an option to disable sending "Alt" by itself?

Thanks for any help you can provide!

When I Alt+Tab away from the UltraVNC viewer (with Scroll Lock off), it sends the Alt key to the remote machine which activates the active app's menu. So when I return to the viewer, anything typed goes to the menu. I'd like UltraVNC stop sending that Alt.

I have tried the Alternate keyboard and ...