I recently upgraded my phone from a Samsung Galaxy Ace 2 to a Samsung Galaxy J3. I have the same phone number but a new SIM.
Some of my contacts can no longer receive texts from me. They get a notification I have sent them a text but they can't open the message.
I have a second problem since getting the new phone. I have lost my contacts Groups and am having trouble recreating them. I can only add some contacts into each Group because when I select Add a Member only a partial list of contacts appears.