What happened is that your bank's (or armored truck company) vault run out of boxes; They went to the Fed for more box; The Fed dispatched some new coins; Once you and your fellow CRHers in your area consumed all the new coins; Next batch from the Fed could be full of silvers.
I've been finding alot also, but not solid boxes. Reminds me of when I first started ordering boxes and getting box after box of shiny new 2000p halves. You just have to be patient and work thru them.