Wp-calypso: Block editor: "Custom Fields" option doesn't work on Simple sites

[davipontesblog]

Steps to reproduce

1. Starting at URL: https://wordpress.com/block-editor/page/DOMAIN
2. Look for caterpillar menu > Options, under Advanced Panels, and check the "Custom Fields" box

What I expected

On atomic sites, the screen will refresh, and the editor adds custom field metaboxes to the bottom of the editor. On simple sites we expect the same thing to happen.

What happened instead

On Simple sites, the Custom Fields panel exists and can be checked, but it doesn't activate anything and the setting isn't actually saved (though the editor will refresh when the box is checked)

Screenshot / Video

Screenshot Simple -- https://cld.wthms.co/08rcuk
Screenshot Atomic -- https://cld.wthms.co/SB8BXB

manual-testing

[chaitanyamsv]

Also reported in 2606733-zen

[mrfoxtalbot]

I do not think Custom Fields are meant to work on simple sites at all. I checked the classic editor and there is not such option:

Following this the logical next step would be to remove this option from the "Caterpillar" menu on all simple sites.

[davipontesblog]

Following this the logical next step would be to remove this option from the "Caterpillar" menu on all simple sites.

Agree. I would think that the action item here would probably be to remove this option in both simple and atomic sites since it's likely not relevant to WordPress.com.

[mrfoxtalbot]

I would be cautious to remove it from Atomic sites unless we have a specific reason to do this. Some old school users (and/or old plugins) may rely on them.

[rickmgithub]

We had to manually add an enclosure tag the other day after a podcast RSS feed didn't work - p2EDhh-Ze-p2

At the moment we have some users asking for duration tags to be added to the RSS feed. I was going to do a test on a simple site by adding the tag manually but also noticed that simple site don't have the custom fields option.

Link to the PodcastP2 post about this too - payqFK-2Y-p2

[gwwar]

Folks investigating should check to see if this is actually whitelisted in Simple and Atomic.

[lizswafford]

Reported in 2722903-zen

[xpurichan]

Another report of confusion with this on a simple site in 2846001-zen.

[xpurichan]

I see that Davi's original screenshots are no longer working. I wanted to add that this option for _Custom Fields_ appear not only in the classic editor but also when using the block editor; despite that I don't believe they ever worked in the block editor...

Setting is found in the block editor by:

1. Visiting a page/post to edit
2. Using the three-dot menu in the top-right corner
3. Select Options
4. Scroll down to the bottom of the page to find and select "Custom Fields". They will never load on the page, and when you re-visit this option after enabling it then you will find that it has turned itself off.

[xpurichan]

Another report in 6442402-hc

[chaitanyamsv]

23326790-hc