How can I refresh iOS homescreen PWA on app reopen

What happened for your PWA is that it saved the session state after you closed it. Starting iOS 12.2, Apple fixed PWA so that it is able to keep PWA session state. However, there is still a problem that Apple needs to fix: it saves the state regardless if you minimize the app (by going to home screen) or close it (by swiping up on app-switch mode). According to this article (https://wespeter.com/posts/ios13-pwa-improvements/) Apple will be fixing in iOS 13 so that it starts your PWA from scratch (start_url) after force quit by swiping up, and only keeps the state when minimize to home screen without force quit and reopen.