I have two masters - light and bold. Bold is an active view. In a font window I double-click a glyph and a window that opens is in Bold mode, but the button that is selected is Light. So to switch to Light mode I have to first click Bold button and then Light.
I was able to reproduce this and filed a bug report. The bug only applies to the button display, though.
So, if the button display annoys you, hitting cmd-1/2 should fix it.
If you prefer the mouse: clicking the (already active) light button still works as expected.
