I opened a support ticket to find out why my builds were not appearing in TestFlight or the Distribution tabs, and after a few days, a support engineer responded. My application included an extension widget. I had inadvertently used an incorrect bundle identifier key (EXExtensionPointIdentifier) instead of NSExtensionPointIdentifier. This caused my upload to fail "plist validations". It appears those validations silently fail. Once I fixed the identifier key and uploaded a new build, all my builds appeared in the list; but now I have 3 or 4 builds sitting in "Pending" status. So for future readers, in case you upload a build and it never appears, maybe randomly check things like plist keys.

Here is the SidebarView toolbar from the app that behaves. .toolbar { ToolbarItemGroup(placement: .automatic) { displayModeToggle sortMenu } } Here is the main content toolbar from the app that behaves. @ToolbarContentBuilder private var windowToolbarContent: some ToolbarContent { if selectedPhoto != nil { ToolbarItem(placement: .navigation) { toolbarTitleCapsule } } ToolbarItemGroup(placement: .primaryAction) { lockToggleButton removeLockButton if selectedPhoto == nil, !showingSlideshow, !(collectionManager.isSelectedCollectionPasswordProtected && collectionManager.isLocked), !filteredPhotos.isEmpty { Button { detailPhotoID = filteredPhotos.first?.id showingSlideshow = true } label: { Label("Slideshow", systemImage: "play.fill") } } } } Here is the Sidebar toolbar from the app that misbehaves. .toolbar { ToolbarItemGroup(placement: .automatic) { sortMenu } } Here is the main content toolbar from the app that misbehaves. @ToolbarContentBuilder private var windowToolbarContent: some ToolbarContent { ToolbarItem(placement: .navigation) { roomDirectoryButton } if selectedRoomId != nil { ToolbarItem(placement: .secondaryAction) { toolbarTitleCapsule } } ToolbarItem(placement: .primaryAction) { showInspectorButton } } Both apps are open source. Their code is up on GitHub.