Screen Mirror Not Working

I used to have the XS Max and could screen mirror my phone to my Samsung tv with no problems. My boyfriend and I would watch videos from my phone a ton. I recently upgraded to the 11 Pro Max and all of a sudden, I’m having a ton of issues. Once the screen mirror is on, the video on the tv will lag really bad with no sound. Then if the video does work, the sound will cut in and out or it just won’t work at all. I’m updated everything, apps and phone, everything is connected to the same network, I feel like I’ve tried everything. I just don’t know why this is happening. It’s extremely frustrating and any help would be greatly appreciated!