I’ve been developping custom themes for not so long, so it is the first time I have a conflict between my theme and a plugin and I’m not really sure how to debug this exactly and fix it.

When my custom theme and Yoast SEO plugin are both activated, there are some issue running the back-end side of my WP (The front-end is totally fine). When I open a page to edit it, and some of my ACF fields appear not filled and I can’t click any of the Yoast options to edit them either, clicking does nothing. It also does not seem to let me show/hide the sections of the post edit page.

Even when I go in the Yoast SEO settings, I can’t edit theme in this situation.

I’ve troubleshoot all plugins with Troubleshoot Mode from the Health Check plugin and tried different themes and my error only occurs when my custom theme (child theme of “blankslate theme”) is activated and that Yoast SEO is activated too.

I’m not sure how to debug this, I’d like help to figure out which steps I should take to debug my theme.

Running PHP 7.1 on an apache server.
WP 5.3.2 and all plugins are updated to last versions.

Plugins currently installed:

• ACF Pro
• ACF: Image Crop Add-on
• Classic Editor
• Health Check & Troubleshooting
• reSmush.it Image Optimizer
• UpdraftPlus
• WP Fastest Cache
• Yoast SEO

The theme is one I developped using a child theme from “BlankSlate” theme as parent.

Image of Javascript errors reported on the console