It quite often didn’t recognize the HDMI output so I’d have to try all kinds of things like rebooting and unplugging/replugging until it would finally output to my screen. Also had some trouble getting it to start charging a few times.
For everyone having this issue, try plugging in the deck to dock with only the HDMI plugged in and no power cable. This worked for my TCL TV. Once the screen screen shows on the TV, you can plug the power cable back in and it should still work
It quite often didn’t recognize the HDMI output so I’d have to try all kinds of things like rebooting and unplugging/replugging until it would finally output to my screen. Also had some trouble getting it to start charging a few times.
Like this guy on r*ddit?:
https://ols.reddit.com/r/SteamDeck/comments/y59bl9/no_signal_when_i_connect_steam_deck_to_tv_using/
Wow that might have helped actually. My third party dock never needed any troubleshooting like that though so I’ve stuck with that.