Auto update permalink sturcture

HI

When I edit the the permastructure it puts the new content into the editable part of the URL, so I’f I’ve added %taxonomy% to the permastructure meaning the editable part becomes “mytax/mypost”.

Problem is if I change the taxonomy, the permalink is not automatically updated. Is there any way to make this work like normal permalinks, so that the structure is dynamically generated from the taxonomy – whatever that is.

To give you some context, posts are being submitted by users with multiple tax terms selected, the admin then selects the yoast primary category then publishes.

Thanks