Fix WordPress Oxygen Login Bug

My WordPress site (with blue-host) is built with Oxygen and hosts a course on Learndash it is showing a strange behaviour: the user sometimes works perfectly on mobile yet refuses to authenticate on desktop. In addition, any password-reset link—whether triggered from the back end or by a front-end user—returns nothing useful. Have reverted to manually setting up user passwords. I suspect website email is not sending (tried changing email address on back end no success - may have caused another issue?)/ cookies or a caching rule maybe blocking the handshake / plugin update issue / a deeper security vulnerability.

I’m not sure whether a particular plugin is to blame, so please start by auditing plugin conflicts first, as requested. Please delete any plugins not being used.

The initial action I remember was in an attempt to save a page edit 2mths ago and the operation threw a global “404 error,” across all pages - installed back up via managewp and have not attempted further edits.

What I need from you: • Identify and resolve the root cause so desktop s succeed exactly as they do on mobile. • Restore a fully working password-reset flow for admins and users.

• Check webmail issues • Provide a concise report of the steps taken, any vulnerabilities found, and the fixes applied (cookies, cache layer,.htaccess, security plugins, etc.).

Please be comfortable using typical WordPress debug tools, Oxygen Builder insights, server logs, and browser dev tools. Once everything is stable I’ll test on desktop and mobile before closing the project. Budget: AUD 30–250 Skills: JavaScript, Web Security, WordPress, CSS, HTML, Debugging, Email Handling, Web Development, Website Optimization