How to resolve Captive Wi-Fi screen issues on iPhone 17?

I have a new iPhone 17 Pro Max on 26.1. I am having problems connecting to public wi-fi spots. When I select a wi-fi network, it will show connected and display the wi-fi icon, however the Captive Wi-Fi screen usually does not come up and it cuts off all internet traffic. I can sometimes circumvent this by forgetting the network, turning off wi-fi then disconnecting from any VPN I have running (usually Nord VPN). Then turning on Wi-fi, selecting the network and most times the Captive screen will come on but also most times I cannot use a VPN. I also cannot rejoin the network automatically and have to go through this routine again. I discovered this problem when I was in Britain a few weeks ago and tried using Wi-Fi on the trains, McDonalds, the Tube and other spots. Is a fix for this in the works?

[Re-Titled by Moderator]

Original Title: Problems with Wi-Fi on iPhone 17 Pro Max - particularly not getting the Captive Wi-Fi screen.