Anyone having trouble adding users?

Now once I add a user. Its gone from the scale the next day. 

Do you still see the user on the People tab in Garmin Connect?

Yup. I actually got my wife to show up on the scale and the next morning she was gone from the scale. Still on the list of people though. I have been in contact with Garmin because I’m also getting crazy body fat readings - they are making me send the scale back to them.

I'm sure Garmin has gone over all of this with you, but when she goes into her own Garmin Connect account, does she see the Index S2 listed with the correct serial number?

Glad Garmin is taking care of this. I'm hanging on to the box and shipping materials for this reason.

Yup. I actually erased her old account and even created a new one - all through the mobile app too. I can see the scale on the account with the serial number. It is the most frustrating thing. When I reset the scale - she shows up. Next morning - poof - gone.

I have a similar problem. Everything works with my account and name, but I can not add my wife on the scale. She has her own account, I invited her but she does not show up on the scale at all. I can connect to the scale with my iPhone 7, but I can not connect with my wife's iPhone 11 with blue tooth. Wifi is setup and working. Does my wife's iPhone need a connection to the scale via blue tooth?

Could finally solve my problem by deleting the invited user (my wife) and re-invite her again. Now it works since yesterday, hope it will stay that way

Just keep tapping.  It eventually will list all the users.  Then once it gets a good weight on them it'll pop up the next time.

Their scale is a finicky piece of rubbish and there are multiple bugs within their software that still need to be solved. The most frustrating part is that Garmin uploads all you contact information before you can even add a user.