сбой произошел только на iPhone XS MAX и вернулся с фона на передний план
[CAGradientLayer _clearContents]: unrecognized selector sent to instance 0x2815c31a0
CoreFoundation ___exceptionPreprocess + 232
1 libobjc.A.dylib objc_exception_throw + 60
2 CoreFoundation -[NSOrderedSet initWithSet:copyItems:]
3 CoreFoundation ____forwarding___ + 1412
4 CoreFoundation _CF_forwarding_prep_0 + 96
5 UIKitCore -[UILabel _startMarquee] + 3332
6 libdispatch.dylib __dispatch_call_block_and_release + 32
7 libdispatch.dylib __dispatch_client_callout + 20
8 libdispatch.dylib _dispatch_main_queue_callback_4CF + 1012
9 CoreFoundation ___CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 16
10 CoreFoundation ___CFRunLoopRun + 1888
11 CoreFoundation CFRunLoopRunSpecific + 452
12 GraphicsServices GSEventRunModal + 108
13 UIKitCore UIApplicationMain + 216
14 金囿 main (main.m:14)
15 libdyld.dylib _start + 4
Он убит уже во время фона, просто iPhone XS max имеет другое отражение.