I am having an issue with filmstrip in the Library module in Lightroom CC 2015.8. There is an overlap that happens where I cannot see the top part of the images in the film strip or the full height of the toolbar. I think I can best explain it with a screenshot. I have tried every combination of Preference, View and Window setting. This is not a problem when I launch ! or relaunch the program or restart the computer but shows up after I have been gone from Library to Develop module and back again. !
Two friends of mine has exactly the same issue ( 1 Mbp and 1 iMac 27", both upgraded to Sierra 10.12.2).
I've tried every kind of combination like you, the next step will be the downgrade to El Capitan and a LR reinstallation.