Gradient Fill Bug in Photoshop CC early 2019 [fixed in recent update]
[update] It looks like the latest update has finally fixed it.
Temporary fix as proposed by Adobe: Go to Preferences/Performance and enable Legacy Compositing. This uses the CPU instead of the GPU which fixes the problem till they patch the bug. It does not disable any of the new features according to Adobe.
I found a bug in Photoshop CC 2019 today. Reported it to tech
support, so hopefully it will be fixed in the next update.
This bug appears when saving to jpeg. When you export to png I found the bug doesn't appear. Haven't tried other export options. When you have multiple layers it will show the other layers as usual and the gradient layer as a solid. The issue is both on windows and on mac.