When you select “toggle folding” on the last header in a note (e.g. your “Thanks!” header in your Welcome note) the footnotes and tags below that header are removed from view as well.
It would be more consistent to consider the Header section ended as soon as a footnote is encountered.
You can escape from footnotes being folded by adding a header with high level (1 or 2). Then the header and the footnotes are a seperate section so that it is not affected if you fold the header before the footnotes header.
In regard to the tags it is a little bit tricky and i do not have an idea. The bad thing here is, that footnotes and tags setted by droping a note onto a tag from the left sidebar both are placed at the end of the text. Writing footnotes and setting tags that way causes an alternate appearance of them