Wp-calypso: Gutenberg Post settings: categories partially displayed

[formosattic]

Steps to reproduce

1. Get import test file with 500+ categories, from here
2. Import file
3. Enable Gutenberg
4. Start a new post
5. Check the Categories in the post settings, scroll down the list

What I expected

Be able to scroll down the list of 500+ categories like it's the case with the new Classic Editor

What happened instead

The list stop after about 35 categories

What I tried

I tried to manually replicate the issue by adding 45 categories in an empty site, but the whole list appeared in the editor.

Could it be that the total number of categories is breaking the display of the whole list?

Alternative until this is fixed without reverting to Classic Editor

Use Quick Edit in WP-admin

Ticket 1566272-zen

[KokkieH]

Had another report of this in Twitter.

Site: southernbellegrace.wordpress.com, 134 categories.

Checked in WP-Admin and there all categories are listed for me. The user has since disabled the block editor for Calypso again.

[KokkieH]

Another report from the support forums.

Site: thevaleofsoulmaking.wordpress.com, 1052 categories. Only the first 100 or so are appearing for me. They have since disabled the block editor.

[KokkieH]

Another here

Site, teepee12.com, 404 categories

[katinthehatsite]

Another report in #1570495-zen ; the user has 135 categories but categories after letter P do not display in Gutenberg editor

[mmtr]

It seems that the lack of a header in the REST API was causing the issue: https://github.com/Automattic/wp-calypso/issues/28615#issuecomment-439391651.

Proposed solution in D20976-code.

[arunsathiya]

1575772-zen

[nagpai]

1576629-zen

[nagpai]

I also wish to note that using the Search option to look for categories beyond the ~35+ category does not show it either.

[edequalsawesome]

Another report here: 1577481-zen

User has 371 categories

[KokkieH]

@mmtr

It seems that the lack of a header in the REST API was causing the issue:

Would this also cause issues with the list of available pages displayed when trying to set a parent page from within the page editor? Report here.

[gwwar]

D21000-code has been deployed which should fix the issue for wp-admin. Please reopen if not 👍

See related: https://github.com/Automattic/wp-calypso/issues/28615

[KokkieH]

Thank you!