A change made for 4.4.0, to compile in delayed-ack support by default but to default the number of acks to 0, was intended to include the popular feature but with it turned off.

The default of 0 is causing lease ACKs to not be written to the database.  The work around without recompiling, is to add:

delayed-acks 1;

To the dhcpd configuration file. Alternatively, you may change the default explicitly in the code to be the desired value:

# define DEFAULT_DELAYED_ACK 0  /* default SO_SNDBUF size / 576 bytes */

or disable the feature at compile time by rebuilding with --disable-delayed-acks.