Azure Mobile App - Strange API result only on .NET - vb.net

Question

Edit:
As of 3/21/2017, even after upgrading from Azure client SDK version 2 to 3.0.1, this is still a problem. So... bump.
I have an Azure Mobile App with custom authentication. I am developing a client for iOS and a client for Windows (VB.NET WinForms).
On iOS, everything works just fine. Registration and Login work, and also a standard API call.
On WinForms, all of the pieces works fine, just not exactly when and how I want (i.e., not all of the time).
Registration works.
Login works.
Standard API call works.
What doesn't work is the standard API call after a Login event.
I have put a console.log() line in my API code, and in all cases, it gets to the line just before the res.json() finishing call.
Here's how I am assigning my user to the client in iOS:
NSString *token = dict[#"token"];
NSString *userId = dict[#"userId"];
MSUser *user = [[MSUser alloc] initWithUserId:userId];
[user setMobileServiceAuthenticationToken:token];
client.currentUser = user;
Here's how I am assigning my user to the client in VB.NET:
Dim token = result.Item("token")
Dim userId = result.Item("userId")
Dim user As New MobileServiceUser(userId)
user.MobileServiceAuthenticationToken = token
MobileService.CurrentUser = user
So, the standard workflow is as follows:
User logs in
Program calls standard API method
On iOS, this works flawlessly. I see the log entry on the API output and it immediately returns the correct information to the iOS app.
On Windows.NET, the following 2 scenarios exist:
If I skip the login process and just call the standard API method (which has been set to access "anonymous"), it works.
If I force the login process and then call the standard API method, the code just hangs forever. The log entry does show up on the API output, but waiting several minutes on the .NET debugger yields no output and no error message. It's just (apparently) hung indefinitely.
So, from what I can tell, the following statements apply:
The API code seems to run the same way every time, no matter which platform is calling the code.
The iOS code seems to run correctly.
Logging in always seems to go fine on either platform.
The .NET code runs fine if the *.json permissions are "anonymous" and no Login attempt has been made.
The .NET code breaks (i.e., hangs indefinitely) if the standard API call is sent after logging in.
This would seem, then, to be related to something happening to the MobileServiceClient during my LoginWithResult method. But, from what I can see, it's the EXACT same code (effectively) on both iOS and Windows.
Does anybody see a flaw in my thinking or code?