previously i never had to go out of them sim to get it working again or enabled
No, it was always like that, since the first release of GSX, our software always required a simulator restart if you disable/enabled it during a session. The ability to do that from the sim has been added only recently to P3D4, but there's nothing in our software that support it explicitly, so a restart has always been required. In order to support the restart in-session from the Options->Add-on, a software must be coded for that.
This becase GSX has ITS OWN "Disable" feature if, for any reason, you want to disable ( there's no reason for doing that, but for troubleshooting reasons you might need it ), from its own menu, and THAT can be used without restarting the sim, it's way faster than using the Options-Add-on menu, and it works with all supported simulators ( FSX and every version of P3D )