I have a CPT "Magentis" and an associated taxonomy "Clients". In the field group for Resource I have tried using the 'taxonomy' and 'taxonomy advanced' field , with "add new" checked.
Adding a new post and taxonomy works, but the taxonomy doesn't get attached to the post: https://prikaza.instawp.xyz/
Also after submission, the form disappears - I need to be able to create another post or refresh the page to see the form again but this doesn't work.
I cannot access the frontend dashboard or admin area to check if the new taxonomy is assigned to the post. Can you please share some screenshots (or a screen record) of the issue? And the code that creates the custom fields, taxonomy on your site?
After submitting the form, you can click on the page URL to add a new post. Refreshing will not work because the form adds some parameters to the URL.