I saw that you opened a ticket for this issue, which is what I would have asked you to do in any case. We'll have a support person helping you there.
I am having a similar issue. When I am accessing remotely, I can see my files, I can usually play a song or perhaps two but very often the files become grayed out and it states the device or files are offline.If I back out of Y and restart I can access the files again or sometimes I need reboot my phone.
I can see that I am connected to a WiFi hotspot and my phone will use data when WiFi is not available.
If I can overcome these stumbling blocks I would likely purchase.
Portsmith100, the next time you lose the connection in that way, would you send us the log from your phone? With younity open, select the Settings, scroll down to the bottom and select Report an issue. Give us a brief description and select Send. We can take a look and try to figure out what's going on.