Multiple Login Prompts - Error 401 - After Logging in

I have a few .NET applications hosted on Windows IIS (One is SharePoint), that I want to protect with ZeroTrust. I am not a web (application) developer…

I am able to get to my site, I am prompted by Cloudflare ZeroTrust - I pass that and then I am forwarded to my website which is proxied through the Cloudflare Tunnel - When I get to my site I am asked to login, I enter my credentials and then immediately after that I am prompted to log in multiple times (5 or more login windows pop up) - and then only part of the site loads and many area display a 401-Unauthorized error message.

Any help would be appreciated - I have four applications I need to configure. Happy to pay for support if someone can tell me how to do that.

In case anyone stumbles across this with the same issue - in my case we were using Windows Authentication (NTLM). We disabled that and are now using Basic Authentication - this change resolved the issue.