CF Access isn't restricting access to a defined URL

I’ve set up CF Access on a WP admin page. The request never redirects to the Access page when I load the URL. I’ve recreated and deleted the application countless times. I’ve tested the exact settings on 4 other domains, and the Access page works correctly.
I can’t tell what’s different about the domain where it’s not working. Proxying is enabled, and the domain isn’t connected to any other servers that could be interfering with the proxy.

Cloudflare Support suggested that it could have something to do with CF for SaaS, which I have enabled but not configured, but I haven’t heard from them in 3 days. I cancelled my $0.00 SaaS subscription since I’m not using it anyway, but it doesn’t expire for another 4 days.

Could anything else that I can control be interfering?

A question in this similar thread has me thinking that it might be that the hosting company, WP Engine, uses Cloudflare. I’ll have to investigate.

Hi there, I’ve replied to your ticket with an update.

From our investigation, this is indeed the reason. Sorry for the inconvenience.

Thanks for verifying that. WP Engine says I can switch off of their Advanced Network (behind CF) to use my own CF account without theirs behind it.

Interestingly, when I load the site directly from their IP, it doesn’t show CF headers. Is this simply an enterprise-level setting they’ve made?