I’ve been running the sensibo integration for years; a few weeks ago it simply stopped working.
I deleted the integration and reapplied the API key but to no avail. It refuses to accept it.
I’ve also created new keys; I’ve deleted every key and created just one, I’ve tried it from the cloud address and the local address, from the MacOS app, web page on MacOS Safari and Chrome, iOS app, web page on iOS.
I don’t think my external IP is blocked because the sensibo app and the website work.
If you are running a DNS blocker like pihole, that may be causing a problem. Also the external access of your browser is not the same as Home Assistant. That’s controlled by setting up and external_url used by cloud services like that one.
Same issue here. It is interesting that someone mentioned DNS as this happened around the same time I had issues with PiHole when upgrading to v6. Although I now have disabled my pihole, the issues with Sensibo remain.