I'm using an old iMac as a secondary display, which since it cannot be upgraded beyond Cataline (10.15.7) requires DuetDisplay to work. But whilst this is fine on other applications, Lightroom Classic is unusable since the display constantly changes it's resolution. It doesn't change size on the screen, but the detail in the photo (when in Loupe for instance) on the iMac loses "focus" and goes grainy, and then back again. This is even looking at a single image on the screen - it constantly reduces in resolution and then corrects itself back again. It makes it impossible to know if an image is sharp or not.
I cannot find any lightroom settings to change to resolve this, and DuetDisplay seemed unable to help.
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