Apple TV Remote App after 15.4.1 update

BCad22 wrote:

It will see the TV name on the phone. My device / phone name will appear in the list on the Apple TV.

But when I choose the Apple TV device from the drop down on the phone, it says connecting and then times out.

Hmmm. A connection / WiFi issue. On some mesh WiFi setups, the security/privacy-inspired "Private WiFi Address" feature that has been On by default since it was introduced in iOS 14 will cause pesky connection issues when trying to use AirPlay... Try turning that setting off for your home network.

Verify that the correct Apple TV unit is selected at the top.

Set up the Apple TV Remote on your iPhone, iPad, or iPod touch - Apple Support

BCad22 wrote:

The remote app on my iPhone no longer works on one of our AppleTVs after updating to 15.4.1. It works for my husband but not for me.

We have removed and readded, entered the code but the remote App does not function.

According to Apple's documentation it shouldn't matter as long as you're running v12 or later, but is your iPhone running the same version of iOS as your husband's? Other possible causes include a Wi-Fi issue or a HomeKit configuration thing involving your respective Apple IDs...

Could you please be more specific about what you're seeing when you attempt to bring up the ATV Remote via iOS Control Center? Can't see the TV's name? Sees the TV name but can't connect?

While it doesn't really address troubleshooting, here's a link to Apple's recommended reading: Control Apple TV with iOS or iPadOS Control Center and Set up the Apple TV Remote on your iPhone, iPad, or iPod touch - Apple Support.