macOS Tahoe Liquid Glass Window Borders

[abedef]

Describe the bug
With the introduction of macOS's Liquid Glass design, some windows now have a thin border that changes based on surrounding colours. Previously, Moonlight's (borderless fullscreen) window would appear flush across the edge of the display, whereas now the display shows a thin line going all around.

Steps to reproduce
Install macOS 26.0 Beta (25A5316i) and launch a Moonlight stream in full screen (or borderless full screen). The edges of the screen are no longer flush – there is a border around it.

Screenshots

Affected games
This is a general streaming issue for macOS 26.0 clients.

Other Moonlight clients
This affects macOS 26.0 clients only.

Moonlight settings (please complete the following information)
Using default full screen behaviour as defined out-of-the-box for macOS clients.

Client PC details (please complete the following information)

• OS: macOS 26.0 Beta (25A5316i)
• Moonlight Version: 6.1.0
• GPU: Apple M2 Max (64GB)

Server PC details (please complete the following information)

• OS: Windows 11
• Sunshine or GeForce Experience version: Sunshine v2025.122.141614
• GPU: RTX 4090
• GPU driver: 576.40

Moonlight Logs (please attach)
Moonlight-1753847333.log

[BitGrub]

Have you found a workaround yet? On iPadOS 26 there's a similar issue, but toggling the fullscreen, or moving the window around a bit fixes the bug. Haven't made the jump to Tahoe yet, so I'm looking for issues in my most used programs first

[abedef]

Unfortunately not, but it seems the border effect may have become less pronounced over the last couple updates because it's been easy to tune out lately. Hard to say, since a window's borders seem to be affected by the colours surrounding it.

This screenshot is taken on macOS 26.0 Beta (25A5346a)