The field types from PluginCollectionItemDeriver each have their own category on the "Add field" form.
In the annotation on PluginCollectionItem, replace "category = @Translation("Plugin")," with "category = "plugin",".
Add a plugin.field_type_categories.yml, with this code:
plugin:
label: 'Plugin'
description: 'Field types based on plugin types.'
weight: 5
(I have no opinion on the weight)
Active
2.0
Code
> In the annotation on PluginCollectionItem, replace "category = @Translation("Plugin")," with "category = "plugin",".
I consider this to be a bug in core.
I'll fix it here (because it's a PITA when using Plugin) , but core should not have broken this!!!