DuckDNS - No apparent ipv4 update activity

Trying to figure out if DuckDNS add-on is actually working for ipv4 update or not.  

After install and configuration, all appears to be working and my sub-domain on the DuckDNS.org site shows an update.  HA is accessible via https:// from the outside; no issues.

The problem is that I'm expecting to see an OK message in the log every 300 seconds, indicating identification of the current ipv4 and an attempt to update my subdomain.  The log doesn't indicate this is happening.  On restart, the add-on parses the security certificates, determines that the current one is valid and skips renewal (all fine) but then no additional activity afterwards indicated in the log.
I'm not receiving any errors either, which is good, I suppose.  But I have no indication that the ipv4 is being updated (or at least that an update is attempted) so I have no faith that, if my ip changes, an update to DuckDNS.org will actually occur.

Is this expected behavior from the add-on?

Thanks in advance for any insight or suggestions!

log entries as follows (subdomain is correct in config; masked here):
[20:49:01] INFO: Starting DuckDNS...

[20:49:01] INFO: Renew certificate for domains: xxxxxxxx.duckdns.org and aliases:

# INFO: Using main config file /data/workdir/config

+ Creating chain cache directory /data/workdir/chains

Processing xxxxxxxx.duckdns.org

+ Creating new directory /data/letsencrypt/xxxxxxxx.duckdns.org ...

+ Signing domains...

+ Generating private key...

+ Generating signing request...

+ Requesting new certificate order from CA...

+ Received 1 authorizations URLs from the CA

+ Handling authorization for xxxxxxxx.duckdns.org

+ 1 pending challenge(s)

+ Deploying challenge tokens...

OK + Responding to challenge for xxxxxxxx.duckdns.org authorization...

+ Challenge is valid!

+ Cleaning challenge tokens...

OK + Requesting certificate...

Warning: Will read cert request from stdin since no -in option is given

+ Checking certificate...

+ Done!

+ Creating fullchain.pem...

+ Done!

s6-rc: info: service legacy-services: stopping

s6-rc: info: service legacy-services successfully stopped

s6-rc: info: service duckdns: stopping

[21:36:13] INFO: Service duckdns exited with code 256 (by signal 15)

s6-rc: info: service duckdns successfully stopped

s6-rc: info: service legacy-cont-init: stopping

s6-rc: info: service legacy-cont-init successfully stopped

s6-rc: info: service fix-attrs: stopping

s6-rc: info: service fix-attrs successfully stopped

s6-rc: info: service s6rc-oneshot-runner: stopping

s6-rc: info: service s6rc-oneshot-runner successfully stopped

s6-rc: info: service s6rc-oneshot-runner: starting

s6-rc: info: service s6rc-oneshot-runner successfully started

s6-rc: info: service fix-attrs: starting

s6-rc: info: service fix-attrs successfully started

s6-rc: info: service legacy-cont-init: starting

s6-rc: info: service legacy-cont-init successfully started

s6-rc: info: service duckdns: starting

s6-rc: info: service duckdns successfully started

s6-rc: info: service legacy-services: starting

s6-rc: info: service legacy-services successfully started

# INFO: Using main config file /data/workdir/config

+ Account already registered!

[21:36:19] INFO: Starting DuckDNS...

[21:36:19] INFO: Renew certificate for domains: xxxxxxxx.duckdns.org and aliases:

# INFO: Using main config file /data/workdir/config

Processing xxxxxxxx.duckdns.org

+ Checking domain name(s) of existing cert... unchanged.

+ Checking expire date of existing cert...

+ Valid till Apr 19 00:50:36 2025 GMT (Longer than 30 days). Skipping renew!