There could be a discrepancy between the CMS web content and the repository file content; some examples and explanations are documented.
All faults described assume that the current developer has not performed user error.
When HTML5 is placed inside Web Content, the saved version has the HTML5 markup moved to outside their original location.
Maybe, CMS parses HTML as HTML4, and cannot parse (but does not delete) HTML5 tags.
When content is saved in the CMS, the resulting markup has whitespace and attribute order changed to meet CMS standards.
If this occurs upon saving the latest CMS content, it is because the last developer to commit changes to the file in the repository did not save CMS-formatted markup.