FabFilter

Please enable the Pro-Q 3 - SOLO Button to either stay depressed
or allow it to be dragged around when enabled. This is great to
determine where issues are or enhancements need to be.

Right now, it looks like it is either on or off.

Thanks for the tips!

You can drag the frequency and change the Q (hold CMD on Mac or CTRL on Windows) while the band is in solo.