Why would an 11 year old house all of asudden start having a major mail poppong issue?

Because it's settling and/or shifting.

" mail poppong " OK , I think I know what you mean. This is not the normal nail pop you get when the home is first built. That happens when damp studs twist and/or shrink. Your issue is out of the ordinary and needs to be looked at by an engineer, this is not good. Either your foundation is failing or a main beam failed. Without on site inspection we can't tell be a structural engineer will be perefct, if not pricey.

Thanks for your answer... Have one concern.. (well, actually now many concerns!).. Could it have anything to do with interior pipes leaking... we had a pipe burst in an interior wall at the end of Sept of last year... though, that doesn't make much sense since all of the pops are down the corners of each exterior wall.. but could it be moisture build up in general throughout the house... any thoughts on this...

Didn't see the typo even after you pointed it out!. you figured it right.. it's not mail popping! Lol! Hope I can keep finding humor in this!

Thanks for your answer... Have one concern.. (well, actually now many concerns!).. Could it have anything to do with interior pipes leaking... we had a pipe burst in an interior wall at the end of Sept of last year... though, that doesn't make much sense since all of the pops are down the corners of each exterior wall.. but could it be moisture build up in general throughout the house... any thoughts on this... didn't see the typo even after you pointed it out!. you figured it right.. it's not mail popping! Lol! Hope I can keep finding humor in this! Can you explain last comments you made... not sure what you mean

I got the pricey part... are you recommending a structural engineer? Is that what you mean?

A structural engineer is trained to understand stresses and strengths in a structure. Your home has movement and an engineer could best determine where the stress comes from and how to fix it. How bad was the pipe burst?