The Pihole is working exactly as it should. The problem lies entirely with the squeezeboxes.
Fortunately there is something we can do on the Pihole that should work around the squeezebox behavior.
The text below is an extract from my notes on installing Pihole 5.x. You may need to adjust if you are using the 6.x beta. I don't remember where I originally found this information.
Replace each "api2.branch.io" below with "baby.squeezenetwork.com".
You will need to ssh into the Pihole.
Use dnsmasq to block sites flooded by badly behaved apps
Create a dnsmasq config file for poorly behaved applications that try to access
blocked sites every couple of seconds. This will extend the Time To Live (TTL)
for those sites so that the app doesn't continuously retry the blocked queries.
This was originally needed with Android phones to improve their battery life.
Keep it enabled for guests.
In a shell running on the Pihole:
sudo -i
In the root new shell running on the Pihole.
cat << 'EOF' > /etc/dnsmasq.d/10-long-TTL.conf
# set TTL to 1 hour for badly behaving phone apps
host-record=api2.branch.io,0.0.0.0,::,3600
EOF
pihole restartdns
exit
Go to the web interface on the Pihole page to whitelist the sites added in
the file above.
http://pihole/admin/groups-domains.php
For each item in the list, follow the sequence of steps below.
Plug the site name into the Domain: box.
api2.branch.io
Cut and paste the following into the Comment: box.
site blacklisted in /etc/dnsmasq.d/10-long-TTL.conf
Do not check the Add domain as wildcard checkbox.
Click on the Add to Whitelist button.
