GoToMeeting cropping

So, I’m back. After leaving ManyCam, I came back.
In Zoom, I’m happy. It’s working well. However, I have a weird problem with GoToMeeting (GTM).
In GTM, the image gets ‘cropped’. This is a well known problem with GTM. However, iGlasses seems to have solved the problem, or is not subject to the problem, because it works fine when sending the signal to GTM, it does not get cropped. In both cases - ManyCam and iGlasses - I’m feeding the VMs with an Atem Mini Pro. Any idea why iGlasses plays nice with GTM but ManyCam does not? Worth investigating.
Thanks!!