Join.Me External Monitor Share Screen Fail

Scenario:

Presenting on join.me and trying to share the screen of an external monitor.

Issue:

Participants see the full screen but only on a portion of their monitor, it's not showing fullscreen as expected.

Solutions Tried:

-Updated the NVS 5200m with the latest driver and reset all settings to default via the Advanced install mode.

-Rebooting computer

-Running Dell diagnostics

-Ensuring all drivers are up to date

-Setting external monitor as main display

Notes:

If I share my laptop screen on Join.Me, it displays as expected. Participants see the full screen on their monitor in full screen.  The only difference I see between the laptop monitor and the external monitors is that the laptop monitor is being driven by the integrated Intel HD Graphics card and the external monitors are being driven by the Nvidia NVS 5200m graphics card.

Coworkers are able to do what I'm doing with no problem on different laptops (HPs).

Question:

Is there some configuration that needs to happen to get this to work or is this some limitation with the hardware?  Or is this some issue with Join.me (which I don't think it is since coworkers can do what I'm doing just fine on their HP laptops)?