@TiagoLoss 

Tokens are not supported as  far as I know - hence a simple free of charge user/password service like noip [dot] com

Yes you need confirm the host once a month, but these literally 2 mouse clicks every 4 weeks within a reminder email - this is worth it.

My opinion.

TP-Link should support more DDNS servers like cloudflare, duckdns and free ones. From the current list, 2 are from China, dynDNS is paid and NO-IP has to confirm the host every month. This is a professional router with lots of features, but it's very simple on DDNS. Custom DDNS does not accept token authentication, login and password is deprecated.

It seems to be some bug. I tested another DDNS service now-dns that uses USERNAME AND PASSWORD and it doesn't work, offline service status.

Nothing is logged. Is the Dynamic DNS function incomplete?

  @TiagoLoss 

On my ER605 V2 and ER7206 it is working perfectly fine.

As I said, noip [dot] com as a simple user/password service.

Question:

Which DNS servers are you using for your ER605 to resolve names?

Can you try to switch to 8.8.8.8 or 1.1.1.1 for testing?

And then reboot the box - just in case?

Any other specific thingies in your setup?

Like double-NAT or DoH?

TiagoLoss wrote

TP-Link should support more DDNS servers like cloudflare, duckdns and free ones. From the current list, 2 are from China, dynDNS is paid and NO-IP has to confirm the host every month. This is a professional router with lots of features, but it's very simple on DDNS. Custom DDNS does not accept token authentication, login and password is deprecated.

@TiagoLoss 

They should add their own TP-Link DDNS service as they do for home routers - would be so simple...

https://www.tp-link.com/de/support/faq/1367/ 

Mikrotik, Meraki - many of them offering their own DDNS services...

  @Hoamboy 

NO-IP in embedded configuration works. The question is Custom DDNS.

  @TiagoLoss 

You want to try ipv64 [dot] net?
Free of charge for 3 hosts and no confirming every month.

Simple username/password and Custom DDNS in Omada.

I've written a detailed instruction of how to use it:

https://community.tp-link.com/en/business/forum/topic/604544?replyId=1194276

  @Hoamboy 

I liked this DDNS, I created the account and did as explained in the topic, but it continues with the offline status. I think it's a firmware bug or it's not active yet.

  @TiagoLoss 

Strange.

Can I see the whole Update URL and config of service in detail?

  @Hoamboy