systemd-networkd won't reload virtual network interface configuraion file

I'm trying to configure a tap interface using systemd-networkd configuration files. I created the files:

/etc/systemd/network/tap_test.network
/etc/systemd/network/tap_test.netdev

with the contents:

tap_test.network:
[Match]
Name=tap_test

[Network]
Description=TEST tap interface
Address=192.168.2.100

tap_test.netdev:
[Match]

[NetDev]
Name=tap_test
Kind=tap

Then in restarted the systemd-networkd service:

sudo systemctl restart systemd-networkd.service

As expected, running ifconfig shows the new tap interface. HOWEVER, when I tried to alter the ip address in the configuration file tap_test.network to end with 101, then tried to restart the systemd-networkd once again, no change coul'd be seen when I ran ifconfig again (the ip address remains the old one).

I also tried to shut down the interface with ifconfig tap_test down and then restart the service, it didn't help either.

How can I make systemd-networkd reload the configuration files?