Think I found a rather annoying bug.
I joined a contact to another accidentally, so I unlinked them and the contacts are separated again. However, when you go into the text messaging app, previous text message conversations from said contact now revert to the old contact details - therefore you need to start a whole new text conversation with the contact you accidentally linked the account to, as the previous one is incorrectly labelled. I liked my 1.5 year old conversation history with my gf, but now instead of her name it's labelled 'Home'. I just tried it on a test contact I created, it happened again.
Sad face.