Is Google Firebase still working

Hello
Is Google Firebase still working
or is there a SSL issue.

I try to connect with an ESP8266 to a Firebase Project but without success
The Datas are available via Browser. I read that this is maybe an SSL Problem.
Any Clue

Is Google Firebase still working

Yes.

or is there a SSL issue.

There were several SSL issues, that's why TLS is used nowadays.

I try to connect with an ESP8266 to a Firebase Project but without success

Don't you think it might help if we can see the code that doesn't work? And a slightly more detailed description of "without success" is usually helpful too.

I read that this is maybe an SSL Problem.

It would be wise to share that knowledge with us. Where is the link to that reading?

This morning I was doing the same sketch with the ESP32 and I did not have any Problem, so it's a Problem with
the ESP8266.

I figured out that there is a Problem with the fingerprint Check this out

In my case it did not help to update the files.

That's not a problem of Google or it's firebase but of the Arduino library programmer. As you didn't post your code and also didn't link to the library you're using, we cannot help.