Confirming that this issue does occur with Ubuntu 18.04.1, i7 3770, with AMD Radeon RX 480, using AMDGPU. I'm also using the kernel ppa 4.17 from June 4th, so I can keep AMDGPU DC enabled and use my primary monitor's DVI-D dual link connection to support 120Hz refresh rate.
I can also confirm that unchecking "Use transparency from system theme", checking "Use transparent background", and re-checking "Use transparency from system theme", results in a stable background. Perhaps "Use transparent background" should check itself if the system theme employs transparency?
Confirming that this issue does occur with Ubuntu 18.04.1, i7 3770, with AMD Radeon RX 480, using AMDGPU. I'm also using the kernel ppa 4.17 from June 4th, so I can keep AMDGPU DC enabled and use my primary monitor's DVI-D dual link connection to support 120Hz refresh rate.
I can also confirm that unchecking "Use transparency from system theme", checking "Use transparent background", and re-checking "Use transparency from system theme", results in a stable background. Perhaps "Use transparent background" should check itself if the system theme employs transparency?