New Phone, not getting texts from son

I don't think switching or changing phones would jumble things up. If you had an iPhone previously, sure, but another Android? I had the last Galaxy phone, last year, and ended up returning it for an iPhone. One problem I was having was it was not sending messages to certain individuals and it would sometimes not receive. Come to find out the Default Samsung messaging app had a little button on the bottom right, that floated, that let you either choose how you want to send the message via phone or SIM CARD. The phone was glitching and would randomly revert to phone when it needed to be in SIM CARD mode to send the message. I had nothing but problems each time I went to try the new "Galaxy" regardless of whatever the revision. They skin the entire UI and bloat it down with Samsung APPS where you have to be logged into their services. SAMSUNG = DA DOO DOO in my Opinion.

I was in the T-Mobile store for over a hour and everyone had to chime in to see if they could fix it, then telling me it was my fault till they found it it was the device and was like oh well, want to upgrade?