A good cleaning probably wouldn't hurt. I have never had one, so I wouldn't know how to clean it proper.
Are you doing anything new or different in your prep? New lump/charcoal/briquets, new seasonings, new injections/marinades? If not, I suppose that leaves the cooker.
Refer working properly?
Not sure where else to look.
Weber Performer with rotisserie ring, 22.5OTS, Maverick 732, Weber Smokey Joe,PBC Smokenator/Hoovergrill, variety of microbrews, Gin and tonic, variety of lighters.