Circuit Disconnected Error: Component State Recovery After SignalR Reconnection in Blazor Server

Context

Blazor Server maintains a persistent SignalR circuit per user session. When network interruption occurs, the browser console surfaces the documented error The circuit has been disconnected and the server-side circuit terminates. Upon reconnection, a new circuit is established, but component state and initialization logic are not automatically restored.

Goal

Determine a reliable pattern for preserving and restoring component state—including transient service data and in-flight async operations—across circuit disconnection and reconnection without duplicating initialization work or leaking resources.

Constraints and Uncertainty

• The framework provides no built-in state serialization or rehydration hook for the reconnection lifecycle.
• Transient services and unserializable object graphs cannot be round-tripped through ProtectedBrowserStorage or similar mechanisms.
• Idempotent initialization must be designed manually; OnInitializedAsync does not re-run automatically on the new circuit.
• Measurement of the performance impact of custom recovery logic is complicated by SignalR latency variance, which masks pure render cost in browser DevTools.

Questions

1. What minimal set of component-level hooks or middleware can capture pre-disconnection state and replay it on the new circuit without requiring every component to implement custom persistence?
2. How can developers verify that transient service instances are correctly re-instantiated and that no stale references remain after reconnection?
3. Does the InteractiveAuto render mode in .NET 8 introduce additional state-recovery complexity when the circuit switches between server and WebAssembly execution?