Four Macs on Fios Not Connecting

Ello!

I have three users whom are trying to connect to their work network via Viscosity. We (tech staff) have a test Mac that we also have tried to connect to their network via Viscosity. We have been unsuccessful. We have been able to connect all four Macs with Viscosity to the network on Comcast, Time Warner, At&T, and Verizon Wireless. The only connection Viscosity does not work on is Verizon Fios. Have you heard of this issue before? Is there some configuration we can try? 

Thank you!