When updating more than one host, ddclient sends updates even if the IP has not changed. This is new in 3.11.1, 3.10.0 does not show this behaviour with the same configuration.

Relevant configuration snippet:

protocol=dyndns2
use=web, web=http://ipv4.nsupdate.info/myip
ssl=yes  # yes = use https for updates
server=ipv4.nsupdate.info

login=your.domain.1
password='HIDDEN'
your.domain.1

login=your.domain.2
password='HIDDEN'
your.domain.2

I ran git bisect and found that the first bad commit is e910204, though looking at the diff, I do not see how that would be related.

For now, I've reverted to the 3.10.0 version, but I'm happy to help/test if I can.