You might have luck and it works with the monitors swapped, but there is no guarantee for that.
The desktop viewer doen’t handle multi monitor systems well currently, sorry. It’s on the list for some time, but there so many things with higher priority that I can’t say anything in regard to when that will be addressed. For now unplugging or dsiabling the second monitor is the only way to get the desktop viewer working on a two monitor system releiably.