I have the same problem. I´m using Lightroom 6 and the latest Adrenalin driver Version 18.8.1
Is there a solution ?
I see four solutions:
1. Deactivate hardware acceleration in Lightroom (which makes editing images pretty slow)
2. Update to Lightroom CC (I tested it with 18.6 on my Fury X and it worked without that issue)
3. Downgrade the AMD driver to a pre-Adrenalin Edition (didn't tested that, but I had no issues before mid 2017)
4. Thank AMD for their great support (aka none) and get an NVidia card