Broken WordPress editing due to WPS Hide Login plugin
Page editing was broken in a WP site that I was asked to update. Unsurprisingly there were a lot of plugins running and it was difficult to track down the reason the Beaver Builder page editor was failing. In the console there were a lot of 403 permissions errors coming back from the WP API.
To help with debugging I set up a copy of the site. As part of the Duplicator Pro install process it disabled the WPS Hide Login plugin. On first login to the test site I was prompted to confirm the admin contact information. Once logged in I found that the page editor was working on the test site.
On the prod site I tried disabling the WPS Hide Login plugin, but it didn't seem to fix the problem. After I cleared all the cookies etc I logged into prod again and was prompted to confirm the admin contact information. After doing this the page editor began working. I was then able to turn WPS Hide Login back in and everything worked as expected.
I suspect that the login redirection from the plugin was skipping the contact confirmation, and that the lack of being confirmed was somehow messing with the API access.