Closing track EQ window in MIX screen BUG!...CB 8.5

-Cubase Pro 8.5-

When in MIX screen and closing a track EQ window…the screen will jump to the Arrangement screen as if you pressed the F3 key. It will take pressing the F3 key 2 times to get back to the MIX screen.

Is this a preference or a glitch in the prefs file?

Cubase Pro 8.5 was just installed yesterday. Also I uninstalled CB Pro 8.

Anyone else see this bug?

Thanks in advance,