I'm on version 3.11.2.

I'm using the command ddclient -daemon=0 -verbose -noquiet for testing.

My /etc/ddclient/ddclient.conf:

daemon=5m
mail-failure=root
ssl=yes
pid=/var/run/ddclient.pid
usev4=webv4
webv4=ipify-ipv4
protocol=cloudflare
login=token
zone=<REDACTED>
password=<REDACTED>
<REDACTED>

All works fine unless I add retry=yes to the config. If I do that and run the command above, I get no output and an exit code of 1.