Lately (let’s say two weeks) Nabu Casa has been very unreliable.
“unable to connect” message in the app and “reconnecting” in the web browser.
At the same time Remote desktop connection to the computer on HA home nework proves that everything is running normaly.
Have tried several devices on several networks.
Nabu Casa account page shows
Status: Connected
Connection resumes finally without intervention.
Surprised to not find posts on this topic.
Am I really the only one experiencing this? 
I’m not having any issues. Where in the world are you?
Have you opened a support ticket at nabu casa?
Rock solid here…
Your connection to Nabu involves every single router between you and them any one of hops could be your culprit.
Estonia
No, I have not.
Did it just now.
Thank you for the suggestion!
I was having an issue just recently (last week) that HA told me it having trouble creating a certificate for connection to NC.
after submitting a support ticket it turns out the only easy way to fix it was to update to the latest HA version (2025.7.1 at the time). Apparently this has been an increasing issue with connections to NC for some time. It was strange that it just hit me last week since I hadn’t made any changes that would have caused it. It was a couple of weeks after I did the update to 2025.6. It really was completely out of the blue.
So it forced me to update my HA version early until waiting till the end of the month. But all is well now.
I was told that 2025.7.2 would have even better error handling than 2025.7.1 but when I was having issues .2 hadn’t been released yet. Maybe if you haven’t you could try to do the update to see if it fixes it.
I’m having very similar connection issues with Nabu Casa, also only since last 2 weeks ago. I have latest version installed, doesn’t make a difference for me. If I restart HA it works for a short while, before its lost again.
Whatever the reasons were, I decided to give the Clouflare a shot.
Well, I am actually shocked how much faster this route is!
For me this is THE solution