As an experienced senior developer with over 8 years of experience in the field, I can confidently say that I tick all the boxes for being an exemplary candidate for your WordPress/PHP theme customization project. With deep expertise in WordPress, PHP and a track record of successfully troubleshooting and fixing various bugs, I have a proven ability to diagnose and resolve functionality issues efficiently.
My proficiency extends well beyond debugging, which aligns perfectly with your needs. Having crafted numerous custom themes, I am familiar with every corner of theme customization. I believe my comprehensive proficiency in CSS, HTML, PHP, and WordPress will drastically aid in addressing the bug impacting your website's functionality and associated theme customization.
Furthermore, my portfolio is not solely restricted to technical proficiency - it covers graphic designing and digital marketing as well. This makes me an attractive candidate as I understand the big picture and optimization your site would require from a design as well as functional perspective. In conclusion, by considering me for this project, you ensure an optimal solution crafted by someone who not only masters each stage of web development but also appreciates the holistic requirements of running a successful online business.