That probably won’t solve your issues, but I can tell you a little about my setup:
I use Navidrome for local Music streaming, it supports the Subsonic API so you will find a compatible client for it on every platform
I have an LG OLED “Smart” TV, but I never connect it to the network, instead I have an HTPC running Linux and Kodi that I use to access Jellyfin (that would solve your performance issue with the Jellyfin app on your “Smart” TV)
I really hope that your issues get solved soon, I wish you good guck