I have a BenQ BL3201 display, connected via HDMI (and a USB-C dongle) to my 2019 15" MacBook Pro. Light grey areas are completely washed out, and appear white. I've attached some photos to demonstrate.
Built-in Display:
External Display:
I've adjusted the brightness, contrast, gamma, and every other setting on the monitor, but none of it resolves this problem. The monitor even has a special 'M-BOOK' mode for MacBooks that doesn't improve things at all. I've gone through every available display profile, and the only one that helps with this issue is 'ACES CG Linear' (but it looks worse in other ways, colours are very dark and muted).
The monitor was previously attached to to a Desktop Linux box, and it didn't show the same issue there.
Is there any setting or tweak that I can use to resolve this issue?