Q: If I open a template for editing, and then choose to view the html code, it seems something is off. And when I go back to Edit (wysiwyg) some blocks are now double. Where did the extra text suddenly come from?
A: After receiving your template, we can confirm this behavior.
The issue stems from the html code being invalid. There are several <P> blocks that are missing the closing </P> block.
When going to the html code the Document-Object-Model is extracted and parsed. Normally the editor is able to deduce what elements are missing and amend the situation. But that is not always the case. Especially if compounded by other overlapping issues. In the provided code there were a <P> with missing </P> inside a <SPAN> block. <SPAN> is allowed inside <P> but not the other way around.
To remedy this, you should do a review of you source code and try and glean what tags are missing of superfluous.
Enclosed is a revised html file, that do not exhibit the issue.
Yellow highlight marks two tag's that has no closing tag's