what's with something?

What's (up) with (something)?

1. What is the meaning or purpose of the something; why is something happening or the case? What's with these tiny portions? For how much the food costs, I was expecting to get a bit more on the plate. We've been waiting to hear what's up company's new expansion plan.
2. What is wrong with something? Hey, what's with your computer? The screen just keeps flashing when I turn it on.

what’s with something?

(American English, spoken) used to ask the reason for something: What’s with all this walking? Can’t we take a cab?