Does that also happen with vsync off? Does the monitor stay at that refresh rate after leaving the game?
I would say that it is normal that the refresh rate is adjusted to match the game rendering. This is what full screen apps do. The operating system defines its own refresh rate and games (and other applications) running in full screen can define their own refresh rate.
Of course it is not a good thing if the refresh rate stays at 60 hz after leaving the game (if it was different from 60 hz before launching). Not sure if this is behavior of vanilla BlitzMax or if
SQ changed something related to this.
My monitor does not even display the refresh rate and also doesn't allow me to set it. It's entirely controlled by the software currently running.