How do I fix Safari not showing all my tabs on MacBook Air with macOS Sequoia 15.4?

Seems the more feedback Apple receives on an issue, the more info. Apple has on which models, and which OS versions are affected, and the more likely the issue will be addressed in a future update. All feedback is carefully read and logged:

Web-form for MacOS: Feedback - Safari - Apple

Web-form for iOS / iPadOS: Feedback - Safari - Apple

Interestingly, the size of the "hole" of missing tabs is equal to the size of the pinned tab areas.

This probably suggests a bug somewhere in the logic of the tab bar, involving that value.

I'm seeing the same problem.

My observation is that this is a function of the number of tabs and the size of the window. With a larger display, I can get all the tabs to appear by making the window wider.

It's a particularly annoying bug, though, because I typically work with many tabs open concurrently.

mine was also disabled. but interestingly, when I clicked it on, then off again, all the tabs appeared.

but when I clicked on a tab, they disappeared again.

it's pretty obvious from this where the bug is occurring, so hopefully they'll get a programmer to chase this down fairly soon.

as I said, this bug is really annoying given my particular workflow.

Unfortunately, Sequoia 15.4.1 just landed but doesn't fix it.

Let's hope this doesn't take too long.

The compact layout really messes up my muscle memory / habits, especially because a bunch of stuff in the compact layout move around (where is your address bar, or even the pinned tabs)

Nice workaround, but I really hope it will be fixed, the separate layout is much better in my view.

(But in the meantime, Compact layout it is)

Try unticking "Always show website titles in tabs" in Safari settings under 'Tabs'. Works for my 27" iMac.