I would say check your squelch setting. It may be set just high enough to not break the scan cycle. Other than that, check your antenna connections. Maybe something has come loose. The only other thing I can think of is if your local dept. changed their power output on their transmit tower and you are not receiving it as strong or they changed the tower they are transmitting on to a different location that is farther away from you. Hope this helps.
I have a BCT15X scanner and it works very well. I am very satisfied with the performance I get. Good luck.