Check your settings in the pages panel - make sure that Allow document pages to shuffle is checked.
If that doesn't fix it, select all the pages, and then make sure that Allow selected spreads to shuffle is checked.
In addition, page 13 should show up as a right-hand-page. The left page of a spread would have to be an even page number.
This is what worked:
Select all pages > Check Allow Document Pages to shuffle
Then I unchecked Allow Selected Spreads to Shuffle, if checked it would do the same thing.
My new #1 page is on the left of the spread and #2 on the right.
Right. You have to work hard to defeat page numbering convention. The only way to do that is to turn off shuffling and force the pages to the wrong side. Readers expect odd numbered pages on the right and evens on the left in languages that read left-to-right.