Minecraft Connection Issue

I recently bought the Minecraft for Windows 10 off the Microsoft store for my PC, and I have the Java JRE, and javaw.exe. My brother has a IPAD and has the Minecraft for IOS as well. We both have Microsoft accounts and we both are each other friends; however, every time I try to join his world, or he join mine it doesn’t connect. What could be the underlying issues in the connection, we both have OPEN NAT, and we both checked the joining multiplayer games in the XBOX settings. Any thoughts would be helpful?