Ad Free Login does not persist on IOS

I have been happy with using Safari on IOS to log in to my Ad Free account for viewing the map.

I liked to be able to just pop open the always running browser, and select the window where ADS-B was, and it opened - with no ads.

Something has happened in the last month or two, where I frequently need to re-enter my credentials to go back to Ad-Free. It works fine for a while, then up pops an Ad and I need to log on again. It is very frustrating.

I am running iOS 18.7.1 on a iPhone 16 Pro.

P.S Is there an iOS APP that can be set up and run continuously with account credentials built in?

Thanks, Don