Missing images

I have an issue with C1 seeming to temporarily lose images

Earlier tonight the amount of images shown in the upload below showed 1112 images. The filter I had on for colour tagging told me I had 1116. I exported them and only 1105 were exported, the amount of images selected for export then changed to 1105 (I didnt touch anything during this time). Neither number was correct so I restarted C1 and now this (1117) is whats showing which is what I should have,

Any idea why C1 is losing them?

https://s17.postimg.cc/hq9q7l6cr/Capture.png