Why it happens
Menu bar icons sit to the right of the notch, never to the left of it. When there are more than fit, macOS doesn’t squeeze them in: the ones that don’t fit just aren’t shown. An app with lots of menus leaves even less room, so icons can come and go as you switch apps.
On macOS 27: the overflow arrow
macOS 27 finally deals with it. When icons don’t fit, a small double arrow appears; click it and the hidden ones show up for a moment. Nothing vanishes for good any more.
Make room: hide what you don’t need
Open System Settings › Menu Bar. Under Menu Bar Controls, choose which of macOS’s own items appear, like Spotlight, Siri or Now Playing. Under Allow in the Menu Bar, switch off apps whose icons you never click; they won’t appear at all.
To tidy by hand, hold Command and drag icons to reorder them, or drag one off the menu bar to remove it.
On macOS 26: squeeze them closer
On macOS Tahoe, two hidden settings pack the icons closer together. Paste these into Terminal, then log out and back in:
defaults -currentHost write -globalDomain NSStatusItemSpacing -int 8defaults -currentHost write -globalDomain NSStatusItemSelectionPadding -int 8
To undo it, run the same two lines with delete in place of write and without -int 8, then log out again. This no longer works on macOS 27, where Apple rebuilt the menu bar.
Or use a menu bar manager
Bartender 7 (paid, for macOS 27) and Thaw (free and open source; its macOS 27 version is still in testing) tuck icons into a second bar you open when you need it. Ice, the popular free one, hasn’t been updated for macOS 27.
Or need fewer icons
Plenty of menu bar icons are there to be glanced at: the battery, the CPU, the weather, your next meeting. SideDock moves those into docks at the edges of your screen and into the notch itself, where they have room to breathe. Its own menu bar icon can be switched off, too.
Try SideDock free for 7 days
Everything unlocked, no card, no account. Pay once if it stays.