Short of a full reset, delete all the other channels on the mux the channel you deleted is on.
Then manually tune the Mux the channel you deleted is on. If you post the channel and your local transmitter the mux and channels you need to delete can be identified.
I have deleted the HD channels as we often don’t have a strong enough HD signal (plus we have a very old TV which is non HD!). I wondered, reading this, if there was a problem in having done this. But no just do another channel search from Installation in the Menu, and it picks up all the channels again.