Hi, thanks for reaching out.
Try temporarily deactivating all plugins not authored by SiteOrigin, do so in one go. If you’re using the Classic Editor, you can leave that activated. Be sure to clear any caching plugins you may have installed before deactivating them.
With all non-SiteOrigin plugins deactivated, test the issue. If the problem is resolved, you’ve found a working baseline. Reactivate your plugins one by one, testing the problem after each plugin activation to see if you can find a conflicting plugin.
If the above process isn’t helpful, enable WP_DEBUG and WP_DEBUG_LOG as outlined here: https://www.wpbeginner.com/wp-tutorials/how-to-set-up-wordpress-error-logs-in-wp-config/, recreate the issue and then check the error log, there might be useful information available there.