I was playing Minecraft Windows 10 Edition when my friends wanted to play with me, and so I went into my world and my friend on his Android device could join without problems and he could play perfectly fine. But my other friend on his iOS device decided to join, but when attempting to join he only sees a small flash of the world then he crashes, since it was a high-end device, I didn't think it was the device but the iOS system or something. To back this fact up, I went onto my other account with my iOS device and decided to join myself, and I received the same results as my friend on iOS. So my friends concluded that it was iOS devices having problems. We then decided for my friend with an Android device to create a new world and it was the same results as above, so we then decided for my friend with an Apple device to create a new world and instead of us crashing as we expected, we instead got a message like "Unable to connect to world" and I got on my Apple device and decided to join my friend that was on an Apple device and I could join successfully. I guess crossplay isn't working properly, this is my conclusion.
Apple and Apple: Yes, can play together
Android and Apple: No, cannot play together
Apple and Windows 10: No, cannot play together
Android and Android: Yes
Windows 10 and Windows 10: Yes
Android and Windows 10: Yes
Apple, Android and Windows 10: No
To me, Apple can only play with Apple
And android and Windows 10 can play together fine.
So to me it's like Apple cannot crossplay.
Android, Apple and Windows 10 could join together in previous versions.
Sorry for the long message.