I've download Visual Studio 2022 and tested the default Blazor Server template (Home/Counter/FetchData). In Visual Studio, IIS Express I can open as many tabs / instances of the application as I want.
When I host the default Blazor Server template in local IIS (Windows 10 Home 21H2, IIS 10) I can only open three instance of the application. The fourth will hang until the first is closed. I see someone has ran into nearly the exact same issue but there is no solution provided.
Anyone know whats going on? I don't understand why IIS Express can handle multiple instnaces but IIS 10 can not. Even Conveyor by Keyoti can support many many tabs compared to IIS 10.
Note: I notice SignalR has limitations on Windows / IIS of 10 concurrent connections, but I'm not even getting two.
Updates
Out of curiosity I tested it on Windows Server 2016 Standard and I can open hundreds of tabs.
I re-installed IIS on Windows 10 to make sure something wasn't wacky.
I've ensured WebSocket Protocol is enabled.
Windows 10 Home supports 3 concurrent connections at the same time, according to Microsoft.
Normal HTTP requests to IIS get process and response returned. So even if you manage to achieve 4 or more at the same time, IIS will work through the request queue and you may not have noticed that your request was slightly delayed unless your individual requests take a while to process.
However with SignalR, a persistent connection is maintained to the server. So if you open one connection per browser tab, and you have 4 tabs open, that 4th tab is going to hang indefinitely until one of the other page has its connection ended (by closing the tab, manually disconnecting via code, or refreshing the page).