Hi sir, I have good experience in WordPress, because I was a part of houzez (themeforest based WordPress theme), I know why you're facing problem there is few ways to varify it, first one check theme for any depricated function and second one your are using any woocommerce extention our any plugin wo is depended on woocommerce and many more. I can find it and resolve it quickly. I know I don't have any review bu I have compete a project a freelance and waiting for my fist review and I hope your my second client who is going to review me, I am 100% sure am not going to let you down. And with this I'll cache plugin and seo plugin and optimize in free for my second review. Am available for next couple of hours to fix this, if you have any further question you can ask me via private message. Regards