M1 MacBook full screen app borders thicken after unlock

Whenever I lock my M1 macbook pro in an app in full screen and then unlock it the borders thicken until I exit fullscreen


MacBook Pro 14″, macOS 15.7

Posted on Dec 31, 2025 11:42 PM

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1 reply

Jan 5, 2026 9:42 AM in response to ccs0716

ccs0716 wrote:

Whenever I lock my M1 macbook pro in an app in full screen and then unlock it the borders thicken until I exit fullscreen


MacBook Pro 14″, macOS 15.7



verify your software is up to date—

The current stable release of Sequoia including bug fixes, security updates is macOS 15.7.3 - I would start there

Keep your Mac up to date - Apple Support

Keep your Mac up to date - Apple Support



M1 MacBook full screen app borders thicken after unlock

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