I have the same issue with GetGroups(). Works in 8.0, not in 9.0.
If I include the name of the domain in the PrincipalContext-call, it works:
var ctx = new PrincipalContext(ContextType.Domain, "domainname");

No repro for me with the given code sample I get the same results from both package versions. Could you please share the full details of the exception and callstack? Could you confirm what runtime are you using - .NET 8.0 or .NET 9.0? Thanks.

I have created a new console application (.NET 9.0) and added the code I mentioned to Program.cs.
Here is the full code:

// See https://aka.ms/new-console-template for more information
using System.DirectoryServices.AccountManagement;

Console.WriteLine("Hello, World!");
var ctx = new PrincipalContext(ContextType.Domain);
var usersearcher = new PrincipalSearcher(new UserPrincipal(ctx));
var users = usersearcher.FindAll().Cast<UserPrincipal>();
var user = users.FirstOrDefault(e => e.SamAccountName == "Here I used a valid user name in our domain");
var groupList = user?.GetAuthorizationGroups().ToList();
Console.WriteLine(groupList.Count.ToString());

Then I added System.DirectoryServices.AccountManagetment 9.0.0 and ran the code
The exception is thrown in the following line:
var user = users.FirstOrDefault(e => e.SamAccountName == "Here I used a valid user name in our domain");

HResult: -2146233033
Message: Invalid URI: The hostname could not be parsed.
Source: System.Private.Uri
Stack Trace:
at System.Uri.CreateThis(String uri, Boolean dontEscape, UriKind uriKind, UriCreationOptions& creationOptions)
at System.Uri..ctor(String uriString)
at System.DirectoryServices.AccountManagement.ADStoreCtx.LoadDomainInfo()
at System.DirectoryServices.AccountManagement.ADStoreCtx.get_DnsDomainName()
at System.DirectoryServices.AccountManagement.ADStoreCtx.GetGroupsMemberOfAZ(Principal p)
at System.DirectoryServices.AccountManagement.UserPrincipal.GetAuthorizationGroupsHelper()
at System.DirectoryServices.AccountManagement.UserPrincipal.GetAuthorizationGroups()
at Program.

I can confirm @jasasa's comment that the problem goes away if I add the name of our domain to the following line:
var ctx = new PrincipalContext(ContextType.Domain, "our domain name");

Appears to be introduced by https://github.com/dotnet/runtime/pull/89787/files#diff-36ef1673850535f3dd5645a5b990a17652b2eaff381d3abaed74fc29278665afR2421

@kumarravik78c is it possible you can provide a fix for this? Thanks

If I include the name of the domain in the PrincipalContext-call, it works:
var ctx = new PrincipalContext(ContextType.Domain, "domainname");

@jasasa @uwer62 do you have examples of what was throwing?

I verified that this throws:
LDAP://CN=John Doe,CN=Users
while this does not:
LDAP://myserver.local:12345/CN=John Doe, CN=Users

@steveharter Currently I only have the example and stack trace I had posted above. Are you looking for something specific?