This depends on your router setup, and how it’s connected to your Internet service. You might want to mention the router type, service provider, and addressing mechanism you’re using. It’s also possible that with certain setups, you won’t be able to externally map the correct port numbers if your router is connected to another router that also NATs its address.
The easiest way to determine the latter is going to a site like “whatsmyip.com” to see if your externally visible address is the external address on your router. Note, this mechanism may no longer work if you are using iOS’s limit IP address tracking mechanism.
I use a TP Archer C2300 router. It worked before I changed my ISP. I went from Spectrum Cable internet to Greenlight Fiber. I have checked with Greenlight and they told me a dynamic IP address would work for me. Spectrum had a dynamic IP address.
I also have a AirTV for my son-in-law to watch the Buffalo Bills. I am in Rochester, NY area, he is in Virginia. That works fine. I don’t have to set up port forwarding for that, it automatically sets up UPND, I think those are the correct letters.
Do you have your Tablo device setup as a static IP on your LAN? Example set it as: 192.168.1.185 so that anytime there is a power outage or a router reset for some reason your Tablo will always be assigned that specific LAN IP. Then when you do that and are using remote connect the company can positively find your Tablo when its being probed for at THAT LAN address.
For several reasons I don’t really like UPNP, although it works fine for many here. Manually configuring the Router port forwards and then saving that configuration will result in perfect stability and better control if you go that route. As a side benefit I avoid the security risks from outside pings against UPNP (but that is really another topic).
If you decide to go this route many here have posted about this, but I would be willing to give you the setup config if you want to see it. Its simple, don’t be intimidated by thinking about manually configuring your router.
You definitely want the Tablo to have a static IP on your home network when you do port forwarding. You definitely do not need a static IP from your internet provider. Also make sure you save changes.
EDIT: Make sure you forward TCP and make sure you have the correct port numbers in both external and internal port numbers.