We've been running into the same issue since iOS 13's release with a very similar crash trace. And we've also had a more than 3x spike in events since the release of iOS 14. We're using performBatchUpdates alongside a FetchedResultsController, and also using performBatchUpdates to animate CollectionViewLayout changes, which doesn't seem out of the ordinary. Fatal Exception: NSInternalInconsistencyException 0	CoreFoundation								 0x1b100d114 __exceptionPreprocess 1	libobjc.A.dylib								0x1c4833cb4 objc_exception_throw 2	CoreFoundation								 0x1b0f1c308 -[CFPrefsSearchListSource addManagedSourceForIdentifier:user:] 3	Foundation										 0x1b22002c8 -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] 4	UIKitCore											0x1b2fdc548 __43-[UICollectionView _updateVisibleCellsNow:]_block_invoke_4.1070 5	UIKitCore											0x1b2fdc000 __43-[UICollectionView _updateVisibleCellsNow:]_block_invoke.1053 6	Foundation										 0x1b22d2f8c __NSFireDelayedPerform 7	CoreFoundation								 0x1b0f8da30 CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION 8	CoreFoundation								 0x1b0f8d634 __CFRunLoopDoTimer 9	CoreFoundation								 0x1b0f8cb14 __CFRunLoopDoTimers 10 CoreFoundation								 0x1b0f86eb0 __CFRunLoopRun 11 CoreFoundation								 0x1b0f86200 CFRunLoopRunSpecific 12 GraphicsServices							 0x1c7081598 GSEventRunModal 13 UIKitCore											0x1b384c004 -[UIApplication _run] 14 UIKitCore											0x1b38515d8 UIApplicationMain 15 App														0x104ffab74 main + 8 (main.m:8) 16 libdyld.dylib									0x1b0c65598 start