Wireless server only allows a single client

I have a BeagleBone Black running Debian configured as an access point using hostapd and udhcpd. A node based HTTP server accepts request on port 80. The device is not connected to any wired network.

From my PC or tablet I can login on the access point, acquire a DHCP lease and request pages from the server. However, when I try to login using a second device, it too seems to work fine, but now the first device can no longer get any pages off the server. Note that when I make the BBB a client on my wireless network (disable hostapd) I can login with any number of devices successfully.

I looked at the network traffic using Wireshark, and found that the station that can no longer communicate with the server keeps sending out ARP requests which are not serviced. Only the ARP request from the latest client to login are replied to. I suspect this is part of the problem, but I cannot think of any reason why ARP requests would not be answered.