UDP connect/disconnect problem on MKR1000

Have an odd problem, I'm not sure if it's supposed to work this way or a bug.

Using Arduino 1.8.2 with MKR1000 board and wifi101 library. I use a Raspberry PI app to connect to the MKR1000 app by WiFi. The MKR1000 is running as an access point.

Originally i call Udp.begin(port) in setup, when I get a connection from the PI and it starts sending data, it is received fine.

However if the PI drops the WiFi connection and re-establishes it, (still sending UDP data to the port), I don't receive any packets on the MKR1000.

The only way to get the MKR1000 to start receiving packets again is to call Udp.stop() and the Udp.begin(port) again.

Since UDP is connectionless, it doesn't seem like you should have to do this. On the MKR1000 the port should stay open regardless of the number of WiFi clients connected to it.

I'm not sure what happens if there are multiple connections sending data and just one drops.

So my question is, do you think it is supposed to work this way or is it a bug?

What is the return value from WiFiUDP.endPacket()?
https://www.arduino.cc/en/Reference/WiFi101UDPEndPacket

I never call endPacket because the MKR1000 is not sending any packets, only receiving.

Oh, so the wifi101 unit just receives packets? So how about the UDP packet send on the Pi? What does it return?