Fix website code

I need a WordPress developer to fix a React-based “TCO Intelligence Tool” embedded on my WordPress site (Astra/Elementor). The tool is working for me sometimes, but for normal site visitors the printer fleet list is empty (brands/models show none). My REST endpoint responds, but fleet data is not persisting/serving reliably.

Current setup

WordPress + Astra Child theme + Elementor

Custom REST endpoints in functions.php

GET /wp-json/camelott/v1/fleet (public)

POST /wp-json/camelott/v1/fleet (admin only, stores fleet in WP options table: camelott_fleet_v4)

POST /wp-json/camelott/v1/tco-enquiry (public, sends email via wp_mail + WP Mail SMTP)

The tool runs on a page using inline React/Babel via CDN

Site uses caching/security plugins (NitroPack + Solid Security). Quote/tool endpoints must be excluded from caching.

The issue

Visitors see: {"ok":true,"count":0,"fleet":[]}

I need fleet data to reliably load for ALL visitors and persist server-side.

Admin deploy should correctly save the uploaded fleet to the database (option) and then visitors should immediately see the populated fleet.

What I need you to do

Diagnose why fleet is returning empty for visitors (option not saving, wrong option key, caching, REST blocked, nonce/auth, permissions, CORS, mixed content, etc.).

Implement a robust fix:

Ensure POST saves to the correct WP option (autoload false).

Ensure GET returns the saved fleet consistently for logged-out users.

Ensure caching is bypassed for /wp-json/camelott/v1/* and the tool page (as needed).

Provide a clean, production-safe solution (no hardcoded passwords in the frontend if avoidable).

Confirm with tests:

Logged-out incognito shows brands/models populated.

Fleet persists after refresh and across devices.

No console errors.

Deliverables

Updated functions.php or a small plugin (preferred) implementing the fix safely.

Any required NitroPack/Solid Security exclusion notes.

Short handover explaining what was changed and why.

To apply, please include

Similar WordPress REST API troubleshooting experience

Your approach and expected root causes