HA stops responding to external webhooks sometimes

Hi, my HA sometimes stops responding to the webhooks made from ifttt or from my iphone. The error on the ifttt.com says:

Action failure message: Timed out waiting for response from http://myaddress.ddns.net:8123/api/webhook/mykey

So the webhooks work most of the time but sometimes stop by no reason and I cannot find what’s the problem. I did check the ip on the ddns service and it is correct. I also have the port forwarding set up and it looks like this:

Could anybody please help me to resolve this problem

I have configured the Ping integration and this is what I found.

The HA is offline sometimes from 5 mins up to 5 hours.

Okay, seems like I figured it out. Turned out my IPv4 seen by a DDNS service was sometimes different from the one I saw when checking it online in the browser. It might be the case that my ISP doesn’t provide me a ip4 and uses some Carrier-grade NAT.
So I’ve set up a DDNS with the IPv6 and now by some reason it also provides a correct Ipv4 address. I’m not sure what I’ve done but it has been already online for 24 hours straight — it was never a case before.
Will post any updates if something happens