I have always been able to cast videos from Google photos on my phone to my smart TV. All of a sudden it doesn't work. I can cast YouTube videos from my phone to the TV. Other people can cast their photos to my TV. So the issue has to be with my Google photos. I've deleted it, reinstalled it, deleted all Google apps and reinstalled them. I was on the phone with Google tech support for an hour and they couldn't help. Their last suggestion was a factory reset of the phone and TV which I don't want to do. Any suggestions is appreciated. Thanks
So many things could be happening here. If you are able to cast using other apps on the phone and not Google photos , then that will narrow it down.
I assume you have already rebooted your phone and router and Chromecast to be safe?
Also you mentioned you have a smart tv.. can you be specific on what one you have?