When a Wysiwyg is added to a MB Group, P tags are stripped out, and so I'm having to apply 'the_content' filter to the output in order to add the tags back in. I have deactivated all plugins except 'Meta Box' & 'Meta Box AIO', so there must be a conflict happening within the Meta box AIO plugin.
It isn't a bug. The subfield value in a group field will save the raw content to the database. When outputting the field value, you can use the function wpautop() to add <p> tag to the WYSIWYG field value. Following the documentation https://docs.metabox.io/extensions/meta-box-group/#sub-field-values
.
