After installing the Creators update, my secondary monitor had terrible vertical stretching (50% of desktop was cut off, what was visible was horribly stretched). If set to only display on the secondary monitor, everything worked fine. But would break again after setting to extend or duplicate displays. After several rounds of Microsoft tech support, the only solution was to roll back to the AMD drivers from ~1 year ago, the last 3 versions that I had on my computer all had the same issue.
For reference I have a 390 GPU