Many small business insurance policies only cover <$10,000 in cash on hand. So plenty of legit businesses get flagged for trying to maintain their coverage and minimize risk.
I worked for a record store in college and we had a Ticketmaster machine (back when they were actual ticket printers). We could only accept cash for tickets, per Ticketmaster policy. So on days that big concerts and sporting events went on sale (like The Grateful Dead, Charlotte Hornets, etc) we would make several large deposits of this cash throughout the day to keep our theft risk under our insurance limit. Under modern structuring/forfeiture laws, we could have lost all that money to the feds and still owed Ticketmaster for the sales we made - because the insurance policy had an exception for government seizure.