Hello,

Firstly, I want to clarify that the mentioned link:

https://www.nuget.org/packages/Microsoft.AspNet.SignalR.Core/

is somewhat misleading as it is about a "Core" component about the previous version of SignalR:

https://www.nuget.org/packages/Microsoft.AspNet.SignalR/

This is different from the SignalR for ASP.NET Core package, which doesn't have version 2.2.3 (currently @1.1.0):

https://www.nuget.org/packages/Microsoft.AspNetCore.SignalR.Core/

I have tested the SignalR integration with the DataSource with version 2.3.0 of the "old" SignalR and it is working as expected. You can test this on your side by updating the demo service to this version, which I have also pushed as a branch at:

https://github.com/telerik/kendo-ui-demos-service/commits/signalr-2.3.0

Note that updating the server side implementation of SignalR package requires the corresponding script version to also be updated:

https://docs.microsoft.com/en-us/aspnet/ajax/cdn/overview#ASPNET_SignalR_Releases_on_the_CDN_17

On the other hand, you can find a runable example using SignalR for ASP.NET Core in the demos:

https://demos.telerik.com/aspnet-core/grid/signalr

This being said, can you clarify which version you are testing with - the old or the new SignalR? Can you send a fully runable project (or a GitHub repository), which demonstrates the problem you are facing as both versions of SignalR are working OK during my tests?
Regards,
Stamo Gochev
Progress Telerik