Plex crashes VM/ESXI when calling it from outside the network

Very peculiar problem, that I can consistently repeat.

Software/Hardware
* Ubuntu 16.10 (yakkety) on a virtual machine using VSphere/ESXI 6.5
* Plex version 1.3.4.3285
* Dell R710 Server
* 4GB ram allocated with the VM; 4 CPUs allocated; 16GB drive space
* Server calls another Ubuntu VM environment for content using Samba
* Ubuntu user name is "plex" for SSH'ing into the server, etc. (similar to what plex registers)

Whenever I'm outside of the network and I use my iPhone 6/Plex App, the server instantly freezes and the VM must be shutdown. This happens whether or not it's accessing the Samba shares where the content is held. Ports are forwarded correctly and I am seeing the server for a few seconds on my phone but as soon as I tap to connect, it freezes. I can't SSH into the server.

Any ideas or experience on this one?

Thank you.