Minecraft Win10 Edition Crossplay problem?

I got Minecraft Win10 Edition (or Bedrock) for the PC just so that I can play with my boys on the PS4, otherwise I would have taken Java.

But to the question:

I have difficulty adding my friends, if I search for them I can add them, but they are not shown to me, nor is it anywhere that they are offline. The same is true of them. How does this work? Are there any settings that are wrong or something?

If you know your way around, please write what it might be.

You have to add each other otherwise it's not good for me either