Urgent: Debug and Fix Two Small Issues in Custom WordPress Course Module

We're seeking a highly skilled WordPress developer with expertise in custom themes, plugins, PHP, JavaScript/jQuery, AJAX, and ACF (Advanced Custom Fields) to urgently review and repair two minor issues in our online course platform. This is a quick job—estimated at about 1 day of focused debugging and fixes—but it's the start of ongoing work, including enhancements, new features, and maintenance for our growing aviation training site.
Project Background:
Our platform uses a custom WordPress setup with courses built via ACF flexible content fields, custom post types (e.g., courses, quizzes), and AJAX-driven progress tracking (e.g., updating user meta for lesson/module completion). The founder is a developer but lacks time to debug these small issues. We've provided extensive code snippets and documentation in the job attachments for your review.
Specific Issues to Fix:

Resume Functionality: The system should remember where a student left off (e.g., last viewed lesson or video timestamp) when they log out and log back in. Currently, it resets or doesn't persist properly across sessions. This involves user meta storage, possibly integrating with video players (e.g., via postMessage or localStorage fallback), and ensuring secure, reliable recall on login.
Progress Indicator Accuracy: The course status (e.g., "Complete" badge or progress bar for modules) doesn't always update correctly when a student finishes a module. It may show "Pending" or "New" even after all lessons are marked done. This ties into our custom AJAX handlers (e.g., ajaxDone() in functions_course.php) and UI updates in course-quiz.js/single-courses.php.

Requirements:

Proven experience with WordPress custom development, including ACF, custom post types, user meta, AJAX endpoints, and frontend JS for dynamic UIs.
Familiarity with e-learning platforms (e.g., progress tracking like in LMS plugins) is a plus—though this is custom, not reliant on third-party LMS like LearnDash.
Ability to debug efficiently using tools like browser dev tools, WP debug logs, and code reviews.
Strong understanding of security best practices (e.g., nonces, sanitization).
Available for urgent start (ideally within 24-48 hours) and quick turnaround.

What We Provide:

Full FTP access.
WordPress admin credentials.
Relevant code files (e.g., single-courses.php, functions_course.php, course-quiz.js) attached here for initial review.
Detailed documentation on the custom progress system.

This is a great opportunity for a top-tier developer to join our team for future projects—we have enhancements planned like advanced analytics, integrations with WooCommerce for subscriptions, and mobile optimizations. Please include in your proposal:

Your relevant WordPress experience (e.g., links to similar fixes).
How you'd approach debugging these issues.
Your availability.

Looking forward to working with you!