Firefox recently changed it's privacy settings in build 102. With this change the defaults settings for Firefox do not allow the "login with google" option. This change affects multiple websites that use this feature. And could cause your login to QxControl to be hindered.
If you are using Firefox and get the error "Unable to process request..." as shown in the screenshot below there is a way to get this working.
Simply click on the Sheild icon on the top left in front of your url/address. Then click the toggle, which is currently on, for Enhanced Tracking Protection to the Off position.
Then refresh the app.qumulex.io page and you should be able to login again using this feature! If it does not work right away, try closing Firefox completely and opening again.