There's certainly some issues with the sticky headers. I was seeing crashes in my analytics and now also locally that appear to be related with the headers (_updatePinnedSectionSupplementaryItemsForCurrentVisibleBounds is in the stack trace):
ObjCRuntime.ObjCException: Objective-C exception thrown. Name: NSInternalInconsistencyException Reason: Frame {{inf, inf}, {0, 0}} does not intersect {{0, 0}, {654, 4779}}
Native stack trace:
0 CoreFoundation 0x00000001888b18dc __exceptionPreprocess + 176
1 libobjc.A.dylib 0x000000018838a418 objc_exception_throw + 88
2 Foundation 0x000000018a9f53cc -[NSMutableDictionary(NSMutableDictionary) initWithContentsOfFile:] + 0
3 AppKit 0x000000018dc6d91c _NSPinnedFrameForFrameWithContainerFrameVisibleFrame + 1288
4 AppKit 0x000000018dc734dc _NSPinnedNonOverlappingFramesForContentFrameVisibleFrame + 284
5 AppKit 0x000000018d55655c -[_NSCollectionLayoutAuxiliaryItemSolver _solveForPinning:visibleRect:] + 1604
6 AppKit 0x000000018d62c2ac -[_NSCollectionCompositionalLayoutSolver updatePinnedSectionSupplementaryItemsForVisibleBounds:] + 432
7 AppKit 0x000000018d9d9d10 -[NSCollectionViewCompositionalLayout _updatePinnedSectionSupplementaryItemsForCurrentVisibleBounds] + 112
8 AppKit 0x000000018d9d73a4 -[NSCollectionViewCompositionalLayout invalidateLayoutWithContext:] + 504
9 AppKit 0x000000018d7880e0 -[NSCollectionViewLayout invalidateLayout] + 68
10 AppKit 0x000000018d78bd90 -[NSCollectionViewLayout _invalidateLayoutUsingContext:] + 60
11 AppKit 0x000000018d8f622c -[_NSCollectionViewCore setBounds:] + 572
12 AppKit 0x000000018daa0114 -[NSCollectionView _clipViewFrameChanged:] + 396
13 CoreFoundation 0x000000018885b484 __CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__ + 148
14 CoreFoundation 0x00000001888bff34 ___CFXRegistrationPost_block_invoke + 92
15 CoreFoundation 0x00000001888bfe78 _CFXRegistrationPost + 436
16 CoreFoundation 0x0000000188839f9c _CFXNotificationPost + 740
17 AppKit 0x000000018cc8635c -[NSView _postFrameChangeNotification] + 240
18 AppKit 0x000000018d92628c -[NSView setFrameSize:] + 1472
19 AppKit 0x000000018d27f6f4 -[NSClipView setFrameSize:] + 176
20 AppKit 0x000000018d9265c8 -[NSView setFrame:] + 300
21 AppKit 0x000000018da86034 -[NSScrollView _setContentViewFrame:] + 248
22 AppKit 0x000000018da86314 -[NSScrollView _applyContentAreaLayout:] + 444
23 AppKit 0x000000018cca79e4 -[NSScrollView tile] + 480
24 AppKit 0x000000018cca77d8 -[NSScrollView _tileWithoutRecursing] + 52
25 AppKit 0x000000018ccdb868 -[NSScrollView _update] + 24
26 AppKit 0x000000018d926080 -[NSView setFrameSize:] + 948
27 AppKit 0x000000018da88574 -[NSScrollView setFrameSize:] + 200
28 AppKit 0x000000018d9265c8 -[NSView setFrame:] + 300
29 AppKit 0x000000018d925714 -[NSView resizeWithOldSuperviewSize:] + 488
30 AppKit 0x000000018d925304 -[NSView resizeSubviewsWithOldSize:] + 360
31 AppKit 0x000000018d926080 -[NSView setFrameSize:] + 948
32 AppKit 0x000000018d757014 -[NSTabView setFrameSize:] + 88
33 AppKit 0x000000018d9265c8 -[NSView setFrame:] + 300
34 AppKit 0x000000018d925714 -[NSView resizeWithOldSuperviewSize:] + 488
35 AppKit 0x000000018d925304 -[NSView resizeSubviewsWithOldSize:] + 360
36 AppKit 0x000000018d926080 -[NSView setFrameSize:] + 948
37 AppKit 0x000000018d9265c8 -[NSView setFrame:] + 300
38 AppKit 0x000000018dcdee60 -[NSPageController _setupTransitionHierarchyWithSourceView:frame:destinationView:frame:forDirection:destinationValid:] + 1256
39 AppKit 0x000000018dcdb2b4 -[NSPageController _animateView:frame:toView:frame:direction:] + 248
40 AppKit 0x000000018dcdbd38 -[NSPageController _navigateToIndex:animated:] + 944
41 AppKit 0x000000018da606f0 +[NSAnimationContext runAnimationGroup:] + 56
42 AppKit 0x000000018da607a4 +[NSAnimationContext runAnimationGroup:completionHandler:] + 100
43 AppKit 0x000000018dcdbe70 -[NSPageController navigateBack:] + 260
