FBA No longer works with Modern Browser

SharePoint 2016 upgraded to the April 2021 CU and now when I open the FBA login page and select Forms base Auth I enter my creds and the page reloads asking if I want to use Windows or FBA. If I open in IE11 or in compatibility mode works just fine

Yes, due to some security changes Chrome made for cookies SSL is now required for SharePoint to login with FBA. If you access the site via SSL, it should continue to work fine.

Also Facing the same problem, it redirects again and again to login screen to opt for windows or fba.
Works fine with Internet explorer.

Yes, unfortunately because of the Chrome changes you will have to setup SharePoint to only use SSL.

How about other browsers… only works with Internet explorer

I think you’ll have the same problem in most browsers as they have enabled the same security features. I would guess it even happens in the latest version of Edge (which is now based on the same code as Chrome).

Thank you… will check with ssl

Is there any alternative for FBA. What we can go for to allow external user other than FBA.

You could potentially use SAML to authenticate against something like Azure Active Directory or Okta. But no matter what you use I think you’ll have the same problem without SSL.