Hello. Thank you for contacting the Toolset support.
I would like to know first your structure. Is the material dropdown shows the parent posts in post relationship?
Can you please share admin access details and once I'll review your structure I will be able to guide you in the right direction.
*** Please make a FULL BACKUP of your database and website.***
I would also eventually need to request temporary access (WP-Admin and FTP) to your site. Preferably to a test site where the problem has been replicated if possible in order to be of better help and check if some configurations might need to be changed.
I have set the next reply to private which means only you and I have access to it.
I see you have one to many post relationship setup between post type Materials and Activities.
You setup a post form for post type Activities and added the parent dropdown for Materials but the parent field is broken.
When I checked the browser's console I can see few Javascript errors.
Could you please try to resolve your issue by deactivating all third-party plugins as well as the default theme to check for any possible conflicts with any of the plugins or themes?
- Do you see any difference? Most probably it could be WP Rocket plugin that cause the conflict.
Can you please check first and see if that help you to resolve your issue.
