I guess your custom user role does not have the required capability to assign terms, which in case of the post_tag taxonomy would be edit_post.
So one thing to do would be giving it to your role—which is most likely not what you would like to do as this does not only affect assigning terms but also a number of other actions).
Another thing you could do is using the map_meta_cap function. If you choose to take on this approach and you have any problems, just say so, and I will try to help you.
Related Posts:
- Custom Taxonomy as checkbox or dropdown
- Taxonomy count per Post type
- Custom Post Type – Taxonomy Dropdown Menu?
- show tags of custom post type ONLY
- Find callback function for custom taxonomy metabox
- How to set individual capabilities on a taxonomy? Or how to re-register an existing taxonomy?
- Registering tags taxonomy for a custom post type
- How to make a custom taxonomy selectable in post publish area?
- Why does querying on post_tags (which has been applied to custom post types) only return posts?
- Tag page with Custom Post Types not returning any posts
- Why are taxonomy terms not saving when using custom meta boxes with radio button taxonomy selectors?
- How to make custom taxonomy into drop down select in a custom metabox
- How can I create an automatic drop down menu with my tags?
- Need help deciding on a taxonomy
- Get Posts by Category, Tag , and CPT Taxonomy
- Topic won’t save for a custom post type — how to debug?
- How to constrain the results to a specific post_type on tag archive page?
- Custom post type, taxonomy and admin bar
- get taxonomies from terms
- Multiple useres editing specified content
- Add other all taxonomies as meta boxes to custom post type
- Automatically / dynamically populating tags in custom post type
- Taxonomy count per Post type
- custom post type tags
- WordPress multiple custom post types capability conflict in a single menu
- Visual editor issue by having multiple tiny mce editors in a CPT
- How to build custom route by adding taxonomies to URL ? ex: www.demo.com/communities/palo-alto/
- Found 2 elements with non-unique id (#_ajax_nonce) and (#_wpnonce)
- How to Filter custom post type by taxonomy?
- A better way to add a meta box to custom post types
- Is it possible to have dedicated page for parent/child taxonomy?
- Only view/edit/delete CPT made by users with the same role
- How to set individual capability of post type in individual category
- WordPress comments_open for specific user role or post type
- Restrict Access to Posts based on Custom User and Post Meta Data
- Giving permission to anyone (non-users as well) with a password to edit a post, possible?
- Custom post taxonomies as tax_query terms?
- Get related posts of child term of custom post type
- Plugin – Combine Meta Box Input Fields into single saveble record
- Limit amount of posts made within a custom taxonomy
- I want to create custom post in which user can share files like PDF & DOCx
- Getting Custom Post Type Meta on Publish
- Issue on Creating Custom Tax Term Dynamically From Another CPT Meta-box On Publish
- WooCommerce Customer Role Delete Custom Post Type
- list taxonomies from a custom post type
- Meta Query Filtering not working on Custom Meta Box using Radio Buttons
- Display a grid of taxonomy terms at root taxonomy page
- How to display “Category and Post_tag” component in a CPT Gutenberg edit screen?
- How to Upload CSV Data into Custom Post Type Data with Metabox programmatically
- Show child custom post types list inside single parent custom post type
- limit value taxonomy based on previous taxonomy value wordpress
- Grouping metadatas into one
- Anon function and add_meta_box
- Several post types on WP Query by tag and taxonomy
- Using meta_query and tax_query at the same time
- Allow Contributor to edit but not update a published post
- Metabox not show in categories custom post type cmb2
- How do I display the taxonomy for a custom post type in an array
- Set a CPT slug as a base name for all the taxonomies
- How to conditionally redirect to the post from a taxonomy page?
- How do I check if the user is on a taxonomy term parent, child or grandchild page?
- How do I display the grand child items of a taxonomy term?
- Taxonomies relations
- Is it better to use WordPress Custom Post Types or Taxonomies?
- Users create/join groups
- Full Custom Post Type List Organised by two Taxonomies
- Repeatable Fields Metabox with Textarea (or wp_editor)
- How to use TinyMCE Editor for one of my custom post meta field?
- Display correctly using metabox.io
- WordPress Doesn’t Generate Taxonomy Archive
- Create Connection Between two post types
- Disable user from updating certain posts
- Suggested Post and Taxonomy structure
- pre_get_posts for custom page builder meta box
- Disable closing on metaboxes
- Edit the author of custom post type
- “Submit for review” for updates on existing posts
- Access to CPT but not to ‘post’ post type
- Allow add new post access to custom post but not wp post for some role
- Deny user access to edit post while allow him to edit custom post type
- Custom post with more than one custom taxonomy
- Show Custom Post Type meta boxes only on Page Edit
- Get the taxonomy of a post hierarchically
- Cannot save CPT meta box
- Create custom post with custom user rules
- Cross reference custom post types
- Adding custom taxonomy in same menu place with two custom post types
- Multiple pages for posts?
- Adding Page Templates to post but it ignored it
- Allow user to only access custom post type
- Parent Page and Breadcrumb URL’s for Custom Post Types Not Working
- Create a Dropdown from Custom Post Type
- Display latest x posts from all categories in Custom Post Type/Taxonomy
- Translating custom post type metaboxes [closed]
- Adding a metabox on a CPT’s submenu page
- How to get all tags of a custom post type by id
- Fixed values for same post translations
- How to Add multiple instance of meta box to custom post type
- How to show featured image block in custom post type for Author?
- How to get list of taxonomy slugs ordered parents>childs?