IdentityServer4 'error' reported by function: "calculateSessionStateResult"

[rsotolongo]

The returned file: "checksession" (https://github.com/IdentityServer/IdentityServer4/blob/main/src/IdentityServer4/src/Endpoints/Results/CheckSessionResult.cs) listen for message events on window object (line 359).

The problem is that the SPA application has a cross-domain iframe sending messages that, at the time to be handled, are reported as error by function: "calculateSessionStateResult" on line 323 because the message does not have any space (JSON: '{"requestType":"DEBUGGER_LOADED"}' in the debugging screenshot).

Is this an IdentityServer4's bug? I'm missing something?