Images changing in filmstrip

Hi, I am very very new to photography and lightroom, but I'm having an issue that I can't seem to find the answer for online anywhere. I'm hoping someone here can help.

When I'm looking at my edited photos in the filmstrip at the bottom, and then click on one, the image is great at first and then after maybe a second or two the image changes a bit. It's really only noticeable on the photos that I've taken of the night sky. The image looks like it gets a little lighter and has less clarity and vibrancy. When I export the image to my computer and view it, it is still the lesser quality looking image that I'm seeing. 

Has anyone had this issue or know how I might be able to change it?

Thank you so much. 🙂