Mac won’t recognize Samsung SMRT TV

I can’t figure out how to get my Mac Studio to connect to my Samsung Smart TV. I have a couple hundred feet of HDMI fiber optic cable running between them, with a 2.1 rated HDMI-HDMI connector near one end. The connection was fine until I moved the TV to another wall and had to add another 50’ fiber optic HDMI to the cable run (hence the need for the connector). The feed worked perfectly before; now the Mac and the TV don’t recognise each other. If I plug the end of the HDMI into a Samsung computer monitor, it works just fine, so I know I’m still getting feed. I know that new 50’ strand is compatible with the TV because I’ve plugged an Apple TV in where the connector now is, and the TV recognized it. Yes, I’ve tested the other HDMI ports. I’m at my wits end, and the professional tech who installed the original setup hasn’t been able to fix it yet.

I don’t know if this is the place to ask about this because it’s probably not a specifically Apple related issue, but I need to start somewhere.

FYI, this is not a personal setup; it is for my church. Thanks in advance.