`objc_setAssociatedObject` and `objc_getAssociatedObject` isn't match

I just want to add a property to UIView like this,

#import "UIView+Extension.h"
#import <objc/runtime.h>

@implementation UIView (Extension)

- (void)setMaxWidth:(CGFloat)maxWidth {
    objc_setAssociatedObject(self, @selector(maxWidth), @(maxWidth), OBJC_ASSOCIATION_ASSIGN);
}

- (CGFloat)maxWidth {
    return [objc_getAssociatedObject(self, _cmd) doubleValue];
}

@end

but sometime it's useful, some time is crashed.

I got the crash info in XCode is this line return [objc_getAssociatedObject(self, _cmd) doubleValue];.

and I got the crash in Bugly is this NSInvalidArgumentException -[_UILabelStringContent doubleValue]: unrecognized selector sent to instance 0x2804fb280.

So Why this happend. I just set a float value but get a _UILabelStringContent value.

PS: My project is in swift 5.0, but I just use Objective-C runtime to add extra properties.

PS2: I used the same code in another Objective-C project, It will not crash.

PS3: It's not always crash.

PS4: I used the this property in UIView and BaseLabel, but only crash in BaseLabel.

PS5: I used it to update frame, I used it in BaseLabel like this.

override func sizeToFit() {
        super.sizeToFit()
        if self.maxWidth > 0 {
            if numberOfLines != 1 {
                let size = self.sizeThatFits(CGSize(width: maxWidth, height: CGFloat.greatestFiniteMagnitude))
                self.size = size
            } else {
                if self.size.width > maxWidth {
                    self.size.width = maxWidth
                }
            }
        }
    }

PS6: Is the crash call by _cmd in objc_getAssociatedObject(self, _cmd)??