I noticed a problem about two weeks ago when I updated from 18.11.2 to 18.12.3, and it continues on 19.1.1. I work late at night, and F.lux is absolutely beneficial to avoiding eye strain and burning, however since I took the 18.12.3 update, F.lux now doesn't change the screen color, and Windows Night Light also does nothing (Though, I have been told that the issue with Windows Night Light is a Windows bug, and it already hasn't been working for a while (before F.lux also stopped working)). It was suggested that I report the bug here, since the problem started after an AMD driver update, and not a F.lux or a Windows update.
CPU: Intel I5-4690K 3.50GHz
GPU: XFX AMD Radeon R9 280X DD