I have no way to set a port forward with a TMobile router. I have an EERO mesh setup and have it set to bridge. I cannot see my dvr outside the house and consistently get an error in diagnostics. I am leaving for a two week vacation on the 16th and would love to be able to access my shows. This is the whole reason I bought Channels and it won’t work. Anyone get TMobile to work outside? Thanks.
You gotta use Tailscale for that since T-Mobile is CGNAT
Considering setting up a Tailscale MESH VPN instance behind your firewall.
- Tailscale has a fee tier with up to 6 users and unlimited number of client devices.
- Only need a single instance on or behind your firewall to access any IP based device on your LAN if you enable advertise sub-net routes.
- Clients for every platform on Earth, including AppleTV
- Will traverse any level of NAT, including carrier graded NAT (CGNAT).
I connect to my HDHR tuner to steam live sporting events. Came in handy yesterday at the pub during a torrential rain storm which knocked out DirecTV. I was the only one at the pub watching the game. 
I am using Tailscale
How do you advertise subnet routes or whatever it is, I am a novice and just want this to work.
Then, Im not too sure what youre asking.
It usually works for me by putting the tailscale-ip:8089 (or whatever port you have) in the Channels dvr app.
Keep in mind that if you're using the internal tailscale tool, you'll be limited on the upload bandwidth. I recommend using the actual tailscale. The installation command is just a couple of lines really
Make sure you install and connect Tailscale to your network on any client device that you want to have remote access to your Channels DVR server. Also, if you are using a HDHomerun tuner then you need to enable the option to share tuners, otherwise they aren't available to your Tailscale network.
It can be done all via the client and web console side GUIs