Like Paul, I have no idea how anything other than a deliberate macro would be changing the size of existing documents.
A zoom setting could make something look very wide, but that would change the apparent size of text as well and would not show up on the ruler.

Below is a screenshot of the ruler for a document set for Tabloid (17x11) with narrow margins.

I recommend, if you need to fix the Normal Template, that you rename it rather than delete it. Many people have no idea of whether they have customizations stored there. Where is the Normal Template / How to Find the Normal Template

You may want to set your printer to one that will not handle paper that size. The screenshot was done setting the printer to Microsoft Print to PDF as the printer driver.
My physical printer would not accept that page size.