Tv tuner not working at all

This may be irrelevant, but I have a question about the TV tuner. I understand that you plug the tuner into the XB1 through USB, not HDMI. I have an Xbox 360 hooked up to my XB1 through the HDMI-in port. In order to play 360 games, I have to use the TV app,
and the TV tuner uses the TV app as well in order to work. I also understand that when you plug in the TV tuner, the OneGuide separates the TV tuner channels from the "HDMI content". My question is this: if I have a TV tuner with a coax cable connected through
the XB1's USB port AND an Xbox 360 connected through the XB1'S HDMI-in port (both at the same time), can I switch between my Xbox 360 and my TV tuner when using the TV app? Thanks for the help!

Is it the offical xbox tv tuner, i have that and it's working perfectly in the back USB port.

Try uninstalling and then installing the tv app while the tuner is in the back port, that might help.

Unfortunately, the digital TV tuner will not work with Freesat. Freesat uses the DVB-S (Satellite) broadcast standard, whereas the Digital TV Tuner only supports DVB-T (Terrestrial).

I'm having a similar problem.

I have a USB TV tuner setup, but I have it disconnected (have done for ages - no USB slots left), but my Foxtel Cable service was working fine.

Then all of a sudden last night as I was watching my cable service all I saw was "TV tuner not found. We are unable to detect your TV tuner. Make sure your TV tuner is connected to your Xbox, and try again."

I slid to the left to open OneGuide and selected HDMI at the bottom of the list but once I selected it it disappears and all I get is the above message on the screen. I am resetting my whole entertainment system settings again but while HDMI is set in TV
Setup (to test commands to the box), cable shows in the TV example on this screen. So HDMI is definitely working but not while trying to open OneGuide.

Not sure how to fix this, but I'll give Carlos Yo's suggestion below a shot to see if that works.

Check if the tv is not defective or try to change the cable... if it doesn´t work, test another TV to make sure the problem isn´t with the xbox itself.

Issue is with software. Have this issue on Xbox One X with Hauppauge tuner and two Xbox One S with their own Hauppauge tuners. All separate and complete setups. Not TV or cable related since they all stopped working the evening of May 5th.

Edit: currently it's the only video media app we have that's not working. Plex, VLC, Prime video all still work.