can't add sims contact error 400

This is still ongoing. I joined mobile Sims for the very first time 24hrs ago and when I woke this morning I had some friend requests (no idea who they are randoms and as far as I can see no way to track the Sim down) and the first accepted FR went fine but all of them after that got this error message.

Are you going to patch this? Making sim friends seems to be a thing with this game but hard to do if it’s buggy.