I am not sure if a nesting of section tags is semantically correct: usually a document divided to sections, sections to articles. However from technical perspective a section should be just as a regular div has no restrictions for a nesting. (And now the section tag is treated rather as a paragraph, which is not correct)
We’ll align the issue asap.
BTW: do you still receive no Helpdesk notifications? Yesterday it looked like we fixed a configuration issue.