One guy who text me his texts are not beeping or alerting me, any idea why?

Weird, his first text is green, and other subsequent ones are blue if that has any bearing.

Blue text message bubbles mean the recipient is using an iPhone and Messages. Green bubbles indicate a non-iPhone OR there was a network issue. I have seen text messages go green to and from an iPhone when there was a momentary wi-fi/cellular issue for the sender or recipient.

Why no beep? Can't say.

if interface sounds stop working on your phone, (calendar alarms in particular) it needs a reboot.

This is a long-outstanding, known-issue

Thanks Ira/V