I find the connection between power automate and survey123 to sometimes feel quite tenuous, especially when the survey is updated.
That being said I have seen the same thing. I'm not sure why, but sometimes power automate changes the survey name in "When A Survey Response Is Submitted" to the "id" of your survey.
If you go to Survey123 and open your survey, look at the address bar in your browser. There will be a long string of numbers and letters. I expect this will be the same as what you are seeing in power automate.