ssh -L 1234:localhost:1234 remote_server binds the RPi's localhost:1234 to remote_server's localhost:1234. You want to bind the port to something on the RPi that the TV can hit, so something like ssh -L 192.168.1.5:1234:localhost:1234 remote_server, where 192.168.1.5 is the RPi's address.
Can you provide more detail? What are the networks/routers/vlans? Which network is the RPi on? What is your ssh command? Is that ufw command on the RPi or the router?
If you run your own mail server and set up everything correctly, including SPF, DKIM, and DMARC, most major providers will still either silently drop your messages or always mark them as spam, unless you pay money for a relay (e.g.: postmarkapp.com).
I have had my domain for 20 years and IP for years, and set up everything correctly, and Microsoft and Google rarely accepted my messages.
If your home IP does not change often, you can use a dynamic DNS service. But your services will be unavailable from the time that your IP changes and the time the DNS record is updated and the cached responses expire.
Servers are all Debian. Family member's laptops are all Debian. I used Debian on my laptops for 20 years, but when Steam Deck switched to Arch, I switched my laptop to Arch to force me to learn it. I have a file with notes of differences between Debian and Arch. Next time I buy a new laptop, I will probably go back to Debian.
I'm at the age that the first train to the event being full is enough to make me go home.