Re: Contacts strange behavior
Does it still happen in Safe Mode? https://support.t-mobile.com/docs/DOC-10696
Does it still happen in Safe Mode? https://support.t-mobile.com/docs/DOC-10696
Does it still happen in Safe Mode? https://support.t-mobile.com/docs/DOC-10696
It might be time to reinstall the firmware, which you should be able to do with Samsung Smart Switch.