When you configure a realm you own and press "Back" to return to the realms list, no realm is selected. However, the options for the previously configured realm are still available, so you can join a realm without it being selected in the menu.

How to reproduce

1. Open the realms menu
2. Click the wrench icon to configure a realm you own (or select it and click "Configure realm")
3. Click the "Back" button at the bottom right
   → No realm is selected/has a white outline, but the options for the realm that was opened in step 2 are still available.

This bug could be fixed in two ways: Either disable the Play button/have no options available like when you open the realms menu from the main menu or display the previously configured realm as selected.