While I'm really glad they've fixed a bunch of important security vulnerabilities, I'm really hoping they fixed the screen flickering issue [1] they introduced in macos 26. It has been driving me insane and even impacts my Studio Display. My work computer is locked to 15.7.3 and has no such issues with either the internal or external display (The same display flickers in 26).
Really wish Apple would get their software quality up from the gutter.
[1] https://www.macrumors.com/2025/12/18/macos-tahoe-studio-disp...
A similar issue happens with Apple Silicon macs and external monitors since long time ago. A fix I found online [1] is to disable GPU dithering using the Better Display app.
The flickering was so bad in my case that the pixels got stuck for some minutes when it happened.
[1] https://www.reddit.com/r/mac/s/TDOa9Lb5rP
I tried that and many other things like changing the default color profile and it and it didn't work. A reboot fixes it for a few days before returning, so it definitely seems like a bug rather than a hardware issue. Both my work MBP (No issues, macos 15) and personal Air (macos26) are apple silicon.
Dang, it worked for me, but my monitor is a 4K BenQ not a Studio Display, must be something else with those then.
Is this related to the 'Screen Mirroring' problem?
When I connect my laptop to a projector, I can select an individual window, or at least I used to be able to select a window and just project that. However, now when I try to select the window, as soon as the mouse cursor gets near the selection button, the button disappears!!! It has been driving me absolutely insane.
I see flickering like crazy when I adjust the screen brightness on my M5 Macbook Pro on Tahoe.
But it's especially obvious when it dims itself based on ambient room brightness, I can actually see the vertical refresh happening as I move from a fully bright room to a dim one.
Wow, I have an M4 MacMini with a Studio Display and haven't seen that. Hope I don't Jinx it when I get home to use it...
iOS also flickers every time I exit an app back to the Home Screen.
Weird green tints for no reason.. bubbles that take so long to inflate, you think your tap was dropped. Round edges that no longer fit the text content. Stupid ellipses at the edges of wrapped text. And all the functions that now take two taps when one used to do it. Text rendered on top of text for crying out loud! Whole view panes clobberin* each other. WebKit is a mess of wasted black bars where menus were hidden. Multiple flashes of white and black between content changes. It hits Apple apps as well as trashing third party layout.
Too many defects to list.
Headline: Apple celebrates 50th anniversary by burning down 40 years of human interface knowledge.