Graphical distortions on high res / high refresh rate monitor

Ever since upgrading to a 1440p 144hz monitor, Ubuntu has been displaying strange graphical distortions. This is one example:

This doesn't happen on Windows, therefore I think this is an OS-specific or software problem and not a hardware defect. It also didn't happen with my old 1080p monitor, and I haven't changed any settings since changing monitors (besides upping the refresh rate).

I'm not sure how to go about troubleshooting this, so any help is appreciated.

Note: I had to take a photo with my phone because screenshotting it didn't capture the distortions.

This also seems to happen spontaneously. Sometimes it works fine, other times the graphical distortions appear. I haven't been changing any settings, so I don't know why it randomly occurs some times and not others.

Output of lspci -k | grep -EA3 'VGA|3D|Display':

01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Tahiti XT [Radeon HD 7970/8970 OEM / R9 280X]
    Subsystem: Micro-Star International Co., Ltd. [MSI] Tahiti XT [Radeon HD 7970/8970 OEM / R9 280X]
    Kernel driver in use: radeon
    Kernel modules: radeon, amdgpu