I can not find the error in my Regex code

With preg_match_all I want to get class and data-attributes in html.

I asked a similar question before. The correct answer to the previous responsibility was done with DOM. But as an alternative to the DOM structure, I also need a regex version.

Source (my old question): https://stackoverflow.com/a/51778865/6320082

Examples and problems: https://regex101.com/r/vSIsac/5