What is your operating system and version (Windows 10, OSX Mojave, iOS 12 etc)?
Win 10
What happened for you (and what you expected to happen)
Unsharp mask either not applied in preview or after "apply", or sometimes preview shows it applied to only a region of image (see attached)
Provide a recipe for creating the problem (step-by-step what you did).
Open .tif file, filters--> sharpen--> unsharp mask...
Screenshots (very handy) or a screen capture/video.
Attached
Any unusual hardware (like tablets or external monitors or drives that may affect things) or relevant other applications like font managers or display managers.
Dual monitor setup, but hardly unusual
Did this same thing used to work and if so have you changed anything recently? (software or hardware)
Used to work... I don't know what changed exactly since it stopped working correctly. I have do have two video cards (UHD 630 and RTX 3080) and have tried both as renderers - the issue happens with both