It is set to multiplayer mode, multiplayer is allowed but when you click play it automatically disables multiplayer mode.
this issue happens to the iPhone versions.
Linked issues
Comments 3
Yes
But even after I turn on the WiFi it is still like that or joinable but says unable to connect to world.
Thank you for your report!
We're actually already tracking this issue at MCPE-44422, so I will resolve and link this ticket as a duplicate.
If you would like to add a vote and any extra information to the main ticket it would be appreciated.
If you haven't already, you might like to make use of the search feature to see if the issue has already been mentioned.
The other issue is being tracked at MCPE-36190.
Quick Links:
📓 Issue Guidelines – 💬 Community Support – 📧 Customer Support – ✍️ Feedback and Suggestions – 📖 Game Wiki
Are you on cellular data?