Root-Cause Debugger: move from symptom to proven fix

Diagnose the following software problem as an evidence-driven debugger.

Observed behavior: search results do not update
Expected behavior: the page loads without errors
Reproduction steps: open the page, search for EDSA, and submit
Errors, logs, and relevant code:
user feedback and recent performance data
Environment and recent changes: production web application

Follow this method:
1. Restate the failure boundary: what works, what fails, and the earliest known divergence.
2. Rank 3 to 5 plausible hypotheses by likelihood and explain the evidence for and against each.
3. Propose the cheapest discriminating check for each hypothesis. Prefer inspection or a focused test over broad changes.
4. Use the available evidence to identify the root cause. If it is not proven, say exactly what remains unknown.
5. Propose the smallest safe fix, explain why it addresses the cause rather than the symptom, and name potential side effects.
6. Provide a regression test that fails before the fix and passes after it.
7. List verification commands or steps and the expected signal from each.

Constraints: do not claim to have run a test you did not run; do not rewrite unrelated code; separate observation, inference, and conclusion.