Hello,
I'm writing this ticket because I recently registered a domain (mebeim.dynu.net) and wanted to setup my router to automatically update its public IP using your API. I have a Technicolor router, and I followed the tutorial (https://www.dynu.com/DynamicDNS/IPUpdateClient/Technicolor), modifying the custom service using telnet, and then adding my username and password along with my hostname in the relative configuration page. Now the problem is that my router keeps telling me that an error occurred, and to check my username/password combination. I'm assuming that my router isn't able to update the IP because of an API request error. The current configuration I'm running is this one:

--- from telnet: dyndns service list ---
custom :
server = api.dynu.com
port = 80
request = /nic/update
update interval = 10800s
retry interval = 30s
max retry = 3

which is the exact same as shown in the tutorial. Also, my configuration on the configuration page of the router:

Configuration
Use DynDNS: Yes
Internet Service: TI_TAG
Username: ***
Password: ********
Dynamic DNS service: custom
Hostname: ***.dynu.net

How can I solve this issue? Why isn't my router able to update the data?

We have feedback from customers with Technicolor routers that the router is able to update the IP address even though it shows error message. Could you please restart your router to get a new IP and see if the IP address of your hostname gets updated?