SignalR One of the identified items was in an invalid format

Question

please tell me, I'm making a game in a bundle of SignalR + Unity. The server is running, the android game is running when you run it on your computer, and when you transfer it to the device itself, I get an error in the StartAsync method:

Error: One of the identified items was in an invalid format. 
Part StackTrace: System.Net.Http.Headers.HttpHeaders.AddInternal (System.String name, System.Collections.Generic.IEnumerable`1[T] values, System.Net.Http.Headers.HeaderInfo headerInfo, System.Boolean ignoreInvalid) (at <efff4cb93af94c0c950db61b78368b54>:0)
System.Net.Http.Headers.HttpHeaders.Add (System.String name, System.Collections.Generic.IEnumerable`1[T] values) (at <efff4cb93af94c0c950db61b78368b54>:0)
System.Net.Http.Headers.HttpHeaders.Add (System.String name, System.String value) (at <efff4cb93af94c0c950db61b78368b54>:0)
Microsoft.AspNetCore.Http.Connections.Client.HttpConnection.CreateHttpClient () (at <fc48509a267447ccb7af409e5c632056>:0)
Microsoft.AspNetCore.Http.Connections.Client.HttpConnection.set_RemoteEndPoint (System.Net.EndPoint value) (at <fc48509a267447ccb7af409e5c632056>:0)
Microsoft.AspNetCore.Http.Connections.Client.HttpConnectionFactory+<ConnectAsync>d__3.MoveNext () (at <fc48509a267447ccb7af409e5c632056>:0)

Unity 2020.3.32 netstandart 2.0

SignalR version 6.0.3

I searched on the Internet, they say that this problem was fixed, but I don't understand how. Has someone solved this problem?