iOS MaterialButton ChangeCanExecute not working

[ty3ukcom]

Describe the bug
Command.ChangeCanExecute() not working. Button just blinking (changing to proper state, and changing back again). On Android working well! Problem only on iOS.

To Reproduce
xaml:
<material:MaterialButton Text="Start" Command="{Binding MakeStartRecord}"/>
part of code:
` private Command _MakeStartRecord;
public Command MakeStartRecord
{
get
{
if (_MakeStartRecord == null)
{
_MakeStartRecord = new Command( ()=>{ isShowRecord = false; }, () => { return isShowRecord; });
}
return _MakeStartRecord;
}
}

    private bool _isShowRecord = false;
    public bool isShowRecord
    {
        get
        {
            return _isShowRecord;
        }
        set
        {
            _isShowRecord = value;
            OnPropertyChanged("isShowRecord");
            MakeStartRecord.ChangeCanExecute();
        }
    }`

Expected behavior
button must to change state to disabled

Smartphone (please complete the following information):

• Device: iPhone6
• OS: iOS 12.1.4