Common Language Runtime error

I recently upgrade from 4.0.0 to 5.0.1. I am getting errors across the board and it looks like it's related to the breaking change in 5.0.0. In my Utils class I have static methods that take in strongly typed objects (see below). I keep getting a Common Language Runtime error when these rules execute. It appears to be because it can't actually execute my method in the Utils class. Suggestions?

I reviewed the Wiki but the examples shown with Utils is simple string parameters, but do not see any examples with extension methods utilizing strongly typed objects. If I lower back to 4.0.0 everything works as expected.

My expression: customers.Where(CreatedDate >= createdFilterParameter).Where(Utils.IsExistingEmail(Emails, newCustomerDataParameter)).Count() < threshold

public static class Utils
{
    public static bool IsExistingEmail(ICollection<Email> emails, Customer customer)
    {
        if (emails is null || customer is null)
            return false;
			
			
	return emails.Any(x => x.Address.Contains(customer.Email));
    }
}	

Thank you in advance for any suggestions - this library is awesome :)

Start by reproducing the reported expression with the strongly typed Utils.IsExistingEmail method on RulesEngine 5.0.1, then compare the behavior with 4.0.0. Investigate the breaking change described in the report and determine whether the expression is supported; done means a confirmed cause with a minimal reproduction and a documented fix or guidance.