Finally, the edit was returning a skill and i was adding the tags to it, but the database refused to update the tags for a reason i dont understand. However, if I directly queried the database to get the skill i edited, and then just copied all the returned from edit view data into that skill and then added tags to it and then saved it, it updated properly. I'm probably missing something about entity that could make it cleaner but right now it works and it's not too obsfucated/hacky so for now it will do.