Dyn Updater 5.4.8, MacOS 10.14.5
And, yes, I have already tried uninstalling and reinstalling the update client. I have tried older update clients:
Here's a list of recent instances where the update client has failed to detect a changed IP address:
Fri May 10 06:49:13 +07 2019 DynIP 101.51.226.129 IP 101.109.121.37 Dyn IP Fail
Sat May 11 06:50:29 +07 2019 DynIP 101.109.121.37 IP 101.51.3.93 Dyn IP Fail
Mon May 13 06:52:57 +07 2019 DynIP 101.51.200.157 IP 101.51.60.118 Dyn IP Fail
Wed May 15 16:01:04 +07 2019 DynIP 188.123.125.141 IP 101.51.67.123 Dyn IP Fail
Thu May 16 17:19:52 +07 2019 DynIP 101.51.80.171 IP 101.51.218.132 Dyn IP Fail
Mon May 20 10:24:41 +07 2019 DynIP 188.123.125.141 IP 101.51.69.224 Dyn IP Fail
Mon May 20 15:25:00 +07 2019 DynIP 188.123.125.141 IP 101.51.69.224 Dyn IP Fail
Mon May 20 17:25:07 +07 2019 DynIP 101.51.69.224 IP 101.51.39.58 Dyn IP Fail
Mon May 20 18:25:11 +07 2019 DynIP 101.51.69.224 IP 101.51.39.58 Dyn IP Fail
Please note that it doesn't always fail and often, eventually, finds the correct new IP. Also, note that I compare the Dyn IP with the real IP only once an hour, so many failed instances will not appear in the above list.
I have saved the log but can't figure out how to attach it.