Do banks get suspicious of cash withdrawals?

I'm curious, do banks typically become suspicious of cash withdrawals? I've heard stories about people having issues with their bank accounts after making large cash withdrawals. Is this a common occurrence? What kind of factors might lead a bank to be suspicious of a cash withdrawal? And what can individuals do to ensure their transactions don't raise any unnecessary flags with their bank? It would be great to have a clearer understanding of this matter, as it seems to be a topic of concern for many people.