[B[Bug] Fuel node may report healthy status while block synchronization is stalled

Summary

A Fuel full node can report a healthy status while block synchronization is stalled, making it difficult for operators to detect that the node has stopped syncing.

Expected behavior

When a node reports a healthy status, it should:

• be actively syncing blocks
• have increasing block height
• reflect stalled synchronization as unhealthy

Actual behavior

In some situations:

• the node process remains running
• API endpoints respond normally
• health checks report OK

But:

• block height does not increase
• peer count fluctuates or drops
• no explicit error is reported.

The node appears healthy while block synchronization is effectively stalled.

Impact

Operators may assume their node is functioning correctly while it is no longer contributing to the network.

This can result in:

• reduced network reliability
• missed participation in testnet activity
• inaccurate uptime assumptions.

Steps to reproduce

1. Run a Fuel full node using official documentation.
2. Allow the node to begin syncing normally.
3. Observe situations where block height stops increasing.
4. Note that health checks and API endpoints continue to report healthy status.