I open up the Minecraft app on my phone and click the realms tab and then click on my friend's realm server. It loads for a bit saying the usual, such as "loading Resource Packs" "This may take a few moments" etc. Then a tab pops up saying "Unable to connect to world". Which after clicking out of the tab brings me back to the main page. 

I've tried switching to a couple different Wi-Fi s, that did not work. I restarted the app and my phone, that did not work either. I've tried being patience and just re-clicking the tab over and over, sadly that did not work either.

I would appreciate any help or advice on how to fix this situation if there is a solution to solve it. Thank you so much!

I inserted a screenshot of what is appearing if you don't understand whats going on.