In my case Gmail messages containing links to Realtor.com stopped opening in the realtor.com app one day and instead started opening in Chrome. On Samsung Galaxy S23 Ultra with Android 14 I found the solution here:

Substitute realtor.com with your app name

Settings/Apps/realtor.com

Under Defaults: Select: Set as Default

Supported Links: Enable

Supported Web Addresses Enable those matching the link URL which isn't opening in the app. If Supported Web Addresses is greyed out, make sure the app is installed and able to open with links here:

Settings/Apps/Choose Default Apps/Opening Links

Find your app (again realtor.com for me), make sure Open Supported Links is enabled.

Tap Supported Web Addresses and enable the addresses you want to open in the app and not the browser.

This gives the option to select whether to open this app instead of the browser when you go to supported web addresses.

In my case Gmail messages containing links to Realtor.com stopped opening in the realtor.com app one day and instead started opening in Chrome. On Samsung Galaxy S23 Ultra with Android 14 I found the solution here:

• Substitute realtor.com with your app name

• Settings/Apps/realtor.com

• Under Defaults:
  Select: Set as Default

• Supported Links: Enable

• Supported Web Addresses
  Enable those matching the link URL which isn't opening in the app. If Supported Web Addresses is greyed out, make sure the app is installed and able to open with links here:

• Settings/Apps/Choose Default Apps/Opening Links

• Find your app (again realtor.com for me), make sure Open Supported Links is enabled.

• Tap Supported Web Addresses and enable the addresses you want to open in the app and not the browser.

This gives the option to select whether to open this app instead of the browser when you go to supported web addresses.