There seems to be a bug here. I am using PDFPageView as a subview of documentView, and I need to set isUserInteractionEnabled = true on each PDFPageView for it to work properly. Without this setting, the interaction does not function as expected. for subView in view.documentView?.subviews ?? [] { if subView.theClassName == "PDFPageView" { subView.isUserInteractionEnabled = true } } extension NSObject { var theClassName: String { return NSStringFromClass(type(of: self)) } }

@Claude31 , @jlilest Thank you for your interest. I've tried various "id" values, but couldn't resolve the issue. Whether it's through indices, enumerate, or direct indexing, the problem persists when accessing the array. I don't want to remove the index, but should I eventually make the choice to do so?