Realms came back on mobile around 1 AM EST for me, but I logged back in at 3 PM EST and Realms is down again, stuck in the loading screen before finally displaying “Realms couldn’t load” even after following the Realms not working help guide. Same exact thing for my friend that is a Xbox player.
Thank you for your report!
We're tracking this issue at REALMS-13894, so we will resolve and link this ticket as a duplicate.
Please note, issues such as these are often due to a temporary service outage, and should be back up and working again soon.