To those who are having an issue with your 4G LTE CellSpot suddenly stop working after a power outage or reset on the Spectrum/Charter ISP network, I have a solution.
I am an independent network engineer and the solution took over two months to find but it was worth it. T-Mobile requires that your ISP open the following UDP ports 123, 500 and 4500 with 4500 being the main port for access to the T-Mobile server that allows the 4G LTE CellSpot to connect to the internet. With that done, the CellSpot is able to download your configuration files and access your user profile so that you can get cell coverage in your home. People have been complaining that it has taken up to 5 days for the CellSpot to sync and start working. But that is not why to takes so long for the CellSpot to start working.
The real reason the CellSpot stops working or takes days to resync is because your profile has become corrupt and it no longer knows your account information on the billing backend of the T-Mobile network. What this means is that you simply have to tell the T-Mobile technical support to release your CellSpot and re-activate it as if it is a brand-new install onto a new account and not adding it to your old account. Because you have a corrupt CellSpot profile, the T-Mobile backend billing software activates a recovery that creates a second CellSpot profile then it locks your profile because thinks that you have two (2) CellSpots instead of one (1). It does not matter how many CellSpots you order at this point; NONE of the will EVER WORK. Verify that you only have one (1) 4G LTE CellSpot on your account and not two (2).
In Summary, verify that Spectrum/Charter ISP has opened UDP ports 123, 500 and 4500 and then request that T-Mobile completely delete your old CellSpot profile because it has become corrupt and no longer works. Then ask them to create a brand-new CellSpot profile for you and your old CellSpot will work again and it only takes up to 30 minutes to show signs that it is loading your new profile correctly. If T-Mobile orders a replacement CellSpot; request that the CellSpot is placed on its own separate account and NOT simply added to your existing account. Then you MUST make sure that you get an RMA (Return Material Authorization) from T-Mobile to return your old CellSpot. Failure to return your old CellSpot within a few days will result in your new CellSpot locking up and giving you the same lights as your old CellSpot (i.e. Green flashing power and Amber (orange) flashing internet lights). This is because the backend billing software thinks you have two (2) CellSpots on your account instead of one. I hope this helps you to get your CellSpot working again.