Try this on safari.
- do not hit click or select any options on the pop window. Do not close it directly.
- on an iPhone select the icon on bottom right that shows all open tabs.
Close all tabs that you have been using. Scroll thru up and down to be sure you close any left over
tabs that had the pop up on from a previous session. IF you wish close all tabs.
- now go clear history and web site data.
- for settings under block cookies, cookies and web sites, I have selected: allow from websites I visit
Though in the past I have had issues on Husker max, these actions above really have limited any popup in the past several months for me.