When I connect through the app they say connected and I can ping them through a Windows machine on the ZeroTier network but I cannot access my home network connected on the Android app.
I can on Windows clients connect through ZeroTier as long as I have all 3 options ticked: Allow Global IP, Allow Managed IP, Allow Default Route. If any of these are unticked I cannot connect on a Windows machine either.
After you connect two devices via Zerotier, theese two devices can only handle traffic between theese two devices. If you want also traffic to the network behind one of theese devices you have to set up a route to that network via the pc with Zerotier installed and masqurading on that pc.