MoFi problem or busted by Verizon police??

[431cruiser]

Hi guys. I wrote a post earlier today, but must not have posted it as there is no record of it. If it appears somewhere twice, I apologize. I'm having to work from cellphone and LTE at the moment, which makes it harder to see the buttons.

In February, I installed a MoFi 4500 v3 router with a new unlimited data SIM card. I disabled the MoFI's wireless, and plugged a D-Link router downstream that I use for wireless as well as a wired connection from a desktop pc. This has worked great until about two weeks ago. At that time, my girlfriend began having trouble accessing my network. Our laptops, my cellphone, and desktop were all still working well, so I thought it was her phone. She said it worked fine at her house and workplace.

Then, last week she had problems elsewhere and went to the Verizon store to see if they could fix it because it was only a few months old. Instead, she came home with a new one with her stuff transferred from the old phone to the new one as they do. When she came to my house, she still could not access my network. All other devices were still working just fine, so I thought she somehow had a corrupt file or unintentional setting that transferred over from the old phone.

Yesterday, I decided to unplug both routers and reboot them to see if that would help her phone. After doing this, I could no longer connect to the internet on any device. I updated the firmware and still no luck. I reset the MoFi a few times and by now I'm connecting directly to it to rule out the D-Link. I even created new networks. The laptops "see" the network according to the wireless network connection shortcut on the toolbar, but can't connect. (I'm not convinced they actually detect the network because wireless devices will show one when it doesn't exist.) I pinged a couple of websites and received timed out responses.

I took the SIM card out of my personal cellphone and tried in the MoFi. A webpage that was on my open browser loaded immediately and I could connect to others. However, after about 5-10 minutes I lost connection again. Does this mean anything? Does it prove that Verizon has booted me since it worked momentarily with a different SIM?

The last thing I tried was a restore on the MoFi and uploaded the .bin file from MoFi. Afterwards, the desktop (which gave me hope since it is a wired connection) indicated that it was connected to the network, but I could not access anything on the web. About 20-30 minutes later, it was back to showing not connected.

So, where do I go from here? Is this how it looks when Verizon boots us? If so, could I use a VPN and get it working again? Are there other areas that I should troubleshoot? I work from home and use a lot of data, so I have to get it running again. I was very pleased with this setup until I unplugged it to try to help my girlfriend with her phone. Now, I don't know what to do.

The first couple of months I used the MoFi, I would log into the Verizon account associated with that SIM card and check the data usage. If I remember correctly, it would show something like "0 used" or "Unlimited". When I checked it today, it actually shows a log of my high usage, but no red flags. In fact, I accidently clicked on a "Buy Data" or something similar link, and a popup appeared showing, "You have Unlimited Data and do not need this add-on."

Thank you all for your help and for allowing me to come here for help.