Everything works fine when using Asp.Net Core SignalR, but there are problems when using Azure SignalR. At this time, we first need to configure Azure SignlaR correctly, and then check how the connection is created in the front-end code. The first thing we need to check is the SkipNegotation option. We need to disable or delete it to connect and use azure signalr normally. Official doc: (you need use skipNegotiation) Configure Page as PDF Create SignalR chat Page Page Create SignalR Chat Page