Why does window capture select the whole screen or produce a blank image?

An overlay used for software brightness or image adjustments can sit above the window you want to capture. The screenshot tool may select that overlay instead, producing a whole-screen selection or an empty-looking window capture. Compare with the overlay-based adjustments temporarily turned off before assuming the underlying application is at fault.

In Settings > Displays > [display] > Image Adjustments, try Prevent overlays from affecting screenshots and screen recordings. This hides the overlay effects from captures, but does not guarantee that macOS's window picker will select the intended window. If window capture still fails, use a screen or region capture, or temporarily turn off the adjustments that need the overlay.

Where supported, Enable color table control provides another way to apply basic brightness and color adjustments without relying on that overlay. Check Current method to see what BetterDisplay is actually using. Enabling a preference alone does not establish that the method is active. Color-table brightness upscaling requires Apple silicon and a suitable XDR/HDR display. Other enabled effects may still require a compositor overlay.

Keep the custom-profile safeguard in place: color-table control can be blocked when a connected display uses a custom color profile. Do not override that protection merely to change screenshot behavior.

If DisplayLink output becomes sluggish while overlays are in use, try turning Prevent overlays from affecting screenshots and screen recordings off for every display using overlay adjustments, including natively connected displays. This is a compatibility check for the capture-exclusion path. It does not establish the cause of a separate app freeze or system-wide stall. If it helps, expect the overlay effects to be visible in captures again.

Also check DisplayLink Manager’s Auto-detect video call overlays option, if present. Turning it off can help isolate overlay-related lag, but may prevent some video-call interface overlays from appearing on DisplayLink screens. This is a separate setting in DisplayLink Manager, not BetterDisplay. DisplayLink’s explanation of the overlay feature describes that visibility/performance tradeoff. Retest your current driver and meeting app rather than assuming a particular driver version always has the problem.

The capture-exclusion setting also prevents overlay effects from appearing in streams and Picture in Picture. It can hide those effects on DisplayLink displays and increase CPU use with some drivers. See Image Adjustments for method selection and capture interactions.