DuckDNS only working localy

Configuration
1

I have a Openreach modem (ONT) conecteed directly to my PT-Link AX5400 (Archer AX72). I use DuckDNS and the IP is set to the same as my ‘Internet IP Address’ is correct. I have Port forwarding setup to forward 8123 to the Raspberry Pi running hassio.
I am using https://MySubdomain.duckdns.org:8123 on my PC and mobile.

I can only access the above DuckDNS domain on my PC and when WiFi is on at home, will not work using mobile data.

Mybe I should give Home Assistant Cloud a go.

Ben

I am Using DuckDNS and the log has the folowing

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 legacy-services: starting
s6-rc: info: service legacy-services successfully started
# INFO: Using main config file /data/workdir/config
+ Account already registered!
[19:58:38] INFO: OK
217.42.170.30

NOCHANGE
[19:58:39] INFO: Renew certificate for domains: zerodog.duckdns.org and aliases: 
# INFO: Using main config file /data/workdir/config
Processing zerodog.duckdns.org
 + Checking domain name(s) of existing cert... unchanged.
 + Checking expire date of existing cert...
 + Valid till Mar  9 21:11:13 2024 GMT (Longer than 30 days). Skipping renew!
[19:59:51] INFO: OK
217.42.170.30

NOCHANGE

And ‘NGINX Home Assistant SSL proxy’, I just restarted it and have the folowing log

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 nginx: starting
s6-rc: info: service nginx successfully started
s6-rc: info: service crond: starting
s6-rc: info: service crond successfully started
s6-rc: info: service legacy-services: starting
s6-rc: info: service legacy-services successfully started
2

On cellular data, can you ping your domain? Are you using your router as the DNS server at home or do you a dedicated server?

3

I had a similar issue and it turned out that my cellular provider had blocked the Duck DNS domains due to their apparent allowing of questionable sources using their services. Worked fine through my normal internet provider but not under cellular. In the end I opted for a fixed domain and it sorted the problem.