Transitioning from one device to another SSL error

Hi all,

This is my first post here, I have looked but have been unable to find what I was looking for and feel a bit lost with SSL certificates and how android deals with these.

I’ve just updated my Note 8 to a Note 10+ and transitioned my wifes phone from a LG V20 to my old Note 8. Both the V20 and N8 were running the Companion App fine with SSL via Duck DNS and Lets Encrypt on a Docker setup just fine. Home Assistant is also set up through Docker.
To facilitate the transition I used Samsung Smart Switch which copies all the data from one phone to the other, and generally does a pretty good job. Home Assistant is really the only app that has suffered this transition. When loading the Home Assistant Companion App it picks up the instance available, and when this is clicked on, the error response is: ’ Unable to communicate with Home Assistant because of a SSL error. Please ensure your certificate is valid’. My suspicion is that the certificate has been copied also and this is what is causing issues.
I have tried clearing certificates on android, I have also deleted the previous devices from integration on Home Assistant. I am able to sign in with SSL via chrome android browser on both phones. removing SSL and changing base config url to http also allows the app to work as intended.
I think that about covers my experience so far. Very thankful for any help.

What URL are you using to connect? Make sure to not use SSL with an IP address as that is not a valid certificate

Hi, thanks. URL is so I think should be ok in that regard.

Do you get the same results on your home wifi and cell data? Does your home assistant configuration.yaml have both an internal and external URL specified?

One more thought, did you have any custom dns settings on the phones that could have got reset?

I do get the same results on home wifi and cell data. I hadn’t tried adding internal and external URLs. I just added it to the general configuration section. This was not successful, I also added this to the configuration.yaml and this was also unsuccessful.
I did have a suspicion that there might have been some custom opendns settings, as I was playing with this a couple of years ago, but I tried these settings and it made no difference. I think my focus with opendns was through the router though, so it may have been a long shot.

I found this which feels very similar to what I am experiencing, but I am not trying to make a self signed certificate

sigh…I was using, adding www fixed the issue. Thanks for the help with trying to figure it out.