Have you tried storing the variable in a cookie or local storage. When an intended page update takes place, remove the cookie or local storage. When the page is loaded without the variable, you can halt the process.
The caveat is that the page must be loaded from the same browser to be able to read the cookie or local storage.
Have you tried having your Wappler page redirect upon load? It would need to get the data out of the URL, then pass it to the next page (which works without the data visible)
This isn’t technically secure if you’re trying to work around a concern related to ensuring no one can see this. But it sounds like you have no choice (unless the page opening string could be changed to a POST request)