Windows 10 update 1803 - malformed packed

[Bill Shirley]

Windows 10 1803 update has caused a problem for several clients running ISC DHCP
on the Linux server.  The PC gets an address (DHCPREQUEST) and a DHCPACK is sent.
It then immediately releases the address and starts over with DHCPDISCOVER again and
again and again.

A wireshark trace on the PC says the DCHPACK (I'm getting two; failover pair) says the
ACK is a "Malformed Packet".  I suspect that I'm sending an option, that despite working
for years, Windows 10 1803 doesn't like anymore.

Note: not all the clients are running a failover pair.

Note: after a rollback of 1803, all is well again.

Has anyone else seen something like this?

Bill