Unfortunately, the size of a full codebase is what will put many folks off, as poking about in the developer console can be time consuming, as well as a no-starter if they’re not on a desktop computer (I’m not, at the mo). Oftentimes when building websites, you have to strip the whole layout right back in order to identify the offending elements (again, that can be time consuming) but this is a valuable exercise in helping a developer narrow down and fix the problem. We’ve all been there at one time or other, and I totally get how frustrating it is. But at the end of the day, if you’re seeking free help via an online forum, you’ll increase the likelihood of getting helpfully specific responses if you cut back the codebase to more easily digestible amounts. CodePen is perfect for that as we (devs browsing in our spare time) can edit on any device (not restricted to the dev console on desktop), and come up with solutions for you on the fly.
Alternatively, you could hire someone to troubleshoot your full codebase for you? (There’s always a trade-off between spending time or spending money)
Good luck with your project.