Thanks for your reply. I ran the app on my m1-mac. the product resides on maccatalyst folder, I thinks it's native. (the icon shows no "no-enter" sign) I checked the crash log. It shows that some infinite loop exists. On iOS, I have no such a phenomenon, it may caused by difference of sublayer between macOS and iOS. To inform, crash log snippet follows; 401 jp.dig-x.GAZZ 0x0000000100935124 -[PeerRoomView drawRect:] + 3736 402 com.apple.UIKitCore 0x00000001a99d1470 -[UIView(CALayerDelegate) drawLayer:inContext:] + 636 403 com.apple.QuartzCore 0x000000018cccf610 -[CALayer drawInContext:] + 312 404 com.apple.QuartzCore 0x000000018cccced8 CABackingStoreUpdate_ + 196 405 com.apple.QuartzCore 0x000000018cd29d0c invocation function for block in CA::Layer::display_() + 64 406 com.apple.QuartzCore 0x000000018cccc28c -[CALayer _display] + 1760 407 com.apple.UIKitCore 0x00000001a9886cd4 -[UIView _dispatchTintColorVisitorWithReasons:] + 324 408 com.apple.UIKitCore 0x00000001a9886a3c -[UIView setTintColor:] + 204 409 jp.dig-x.GAZZ 0x0000000100935124 -[PeerRoomView drawRect:] + 3736