Airplay from iPhone 13 to Samsung tv or iMac not working

My 2017 iMac and Samsung smart tv simply won't show up for airplay devices or even for screen mirroring with my iPhone 13. I have tried all the steps showing up online to get it to work. I have them close to each other, have reset, did the updates earlier this weekend, still nothing seems to help on either the computer link or to the tvs which do have the Airplay turned on, and are on the same wifi also.

This is my first time trying to do this with my phone, though several years ago I was using screen mirroring with my iPad and this iMac okay.

We are using Starlink for our internet and wifi. The screen mirroring on iPhone just spins endlessly it can't seem to find any devices, and when I try to cast a video from an app via Airplay 2, no devices show up. I am currently updated to IOS 17.4 on the phone. The iMac is also updated to Ventura 13.6.5.

Any suggestions?