spinning wheel in develop module near view mode drop down

Does anyone else have a spinning wheel near their view mode drop down in the develop mode.  Not sure when this started, but it doesn't stop no matter how long I have LR open.  At first I thought it was processing thumbnails behind the scenes or something, but it is constant.  Will attach screen shot below to show it's location.  Obviously you can see just part of the spinning wheel in stop motion.

I mostly ignore it, but it is one of those things that I'm sure there is probably a simple solution, I just don't know what it is?