Using a Sony FDR-AX53 camcorder via HDMI and a Logitech C920 webcam via USB on my new Webcaster X2. I get video from both sources, PIP works, all the shortcuts from 1-8 on the keyboard work, except the Tab button to switch full screen video source does not work. Only 1 source works, when I press the Tab button it does a flicker on th screen but doesnt switch. I have updated the Webcaster X2 already, switched keyboards, changed the usb camera output resolutions, tried a different webcam, same issue. Would appreciate any advice please, thank you.
I would recommend to try a factory reset of the unit:
Click on Settings, Backup & Reset, Factory Data Reset, Reset Device. This will return it to factory default with the current firmware. Hopefully this should resolve the issue!
Thank you, I should have thought about that, it seems to have done the trick 
Just an update on this issue. Since I took the network switch out and changed the resolution to 720 I have had no issues with the TAB feature. It’s been working great. Not sure why either of these points were issues. Just wanted everyone to know.