Xbox not reading HDMI

Hello all, this might be a bit of a loaded question as I’m going to provide some backstory because I think I might be in a unique situation.

So I bought a used Xbox one X about a month ago and it’s been working fine up until a couple days ago when the display started randomly flickering. I changed one of the display settings (admittedly I don’t remember which) and it stopped flickering and worked fine for a couple days after that. However now when I try to turn it on my TV keeps showing that there’s no HDMI input despite my Xbox being turned on, having a functional HDMI cord plugged into the correct port, and me being on the correct HDMI input. I have tried other HDMI cables and other TVs and it doesn’t seem to work on anything. I’ve been unsuccessful with the holding down eject and sync method as nothing seems to happen or my Xbox will make that little failure noise (like it does when you try to eject a disc if there’s no disk in the console).

I would love it if there was a way to fix this but the other part of my question may or may not be applicable at all. I ended up getting this Xbox after returning a different one after only a couple days because games and apps generally wouldn’t load and would freeze and crashed the whole console almost every time I turned it on so I assumed it was faulty. Is there potentially something I’m doing that’s making two newly purchased used X boxes not work? or is this just a weird coincidence of having two problems in a row?

:)