Connection times too long

I’m using ZeroTier to connect between a Raspberry pi running Linux (Raspbian) and a Windows machine (Win10). The Raspberry pi is using a 4G connection, but the results are the same when connected via Ethernet… The Raspberry pi reports when it can ping 8.8.8.8, and again when it can ping my Windows machine.using ZeroTier. The connection to the Windows machine takes at least 90 seconds longer than the ping to GOOGLE. So why is ZeroTier so slow to connect - even on a fast connecton? Is there anything I can do to speed up the connection process?