GetEnterpriseUsersWithMarkerAsync throws NRE when evaluating Entries

[watfordsuzy]

• [X] I have checked that the SDK documentation doesn't solve my issue.
• [X] I have checked that the API documentation doesn't solve my issue.
• [X] I have searched the Box Developer Forums and my issue isn't already reported (or if it has been reported, I have attached a link to it, for reference).
• [X] I have searched Issues in this repo and my issue isn't already reported.

Description of the Issue

If I include an externalAppUserId to a call to GetEnterpriseUsersWithMarkerAsync the resulting marker based collection has a null Entries field.

Steps to Reproduce

string? marker = null;
do
{
    var result = await client.UsersManager.GetEnterpriseUsersWithMarkerAsync(marker, externalAppUserId: "user_id");
    foreach (BoxUser user in result.Entries) // NullReferenceException (result.Entries)
    {
        // ...
    }

    marker = result.NextMarker;
}
while (!string.IsNullOrWhiteSpace(marker));

Expected Behavior

The list of entries is enumerated.

Error Message, Including Stack Trace

This is in a durable function app and the stack trace is a bit useless.

Screenshots

Versions Used

.Net SDK: 5.7.0 Windows: dotnet-isolated|8.0