Windows Forms - ErrorProvider overlapping icons

Question

I'm using a custom icon in my ErrorProvider with

ErrorProvider.BlinkStyle = ErrorBlinkStyle.NeverBlink

I've got a problem with overlapping icons using code that is similar to this one:

public partial class TestForm : Form
{
    private ErrorProvider _errorProvider1;
    private ErrorProvider _errorProvider2;
    private CheckBox _control1;
    private CheckBox _control2;

    //...


    private void ValidateAll()
    {
        _errorProvider1.Clear();
        _errorProvider2.Clear();

        _errorProvider1.SetError(_control1, string.Empty);
        _errorProvider2.SetError(_control2, string.Empty);

        if(Validate(_control1.Checked))
        {
            _errorProvider1.SetError(_control1, "Error1");
        }

        if(Validate(_control2.Checked))
        {
            _errorProvider2.SetError(_control2, "Error2");
        }
    }

    //...
}

I'm interacting with _control1 while _control2 has some error (is Checked), thus _errorProvider2 has some error set. Everytime method ValidateAll is called it will correctly set _errorProvider1 for _control1 but _control2 _errorProvider2 will keep drawing extra icons without erasing old ones.

Starting view

After 'clicking' _control1 multiple times

When interacting with _control2, _errorProvider2 will go back to normal, but _control1's _errorProvider1 will do the same until it is 'clicked'.

After 'clicking' _control2

Please note that underlying Control doesn't affect it; it doesn't have to be CheckBox.

What I tried:

• Using only one ErrorProvider per Form/Control,
• Focusing each Control before setting ErrorProvider,
• Not clearing ErrorProviders

Any help is much appreciated, thanks!