I also have the same issue, I just purchased Pro as well.
There is a temporary fix, at least for me…
While under the Elementor Theme Designer, simply refresh the browser tab, reloading the Elementor Designer.
Then do all the styling updates related to the broken page, then click the green Update. This only works once though. If you make more styling changes, it will break the page again. In other words, you can only click the green Update button once for every browser tab refresh.
