Encryption With Certificate

 I am trying to create a encrypted row in my database
Everything here worked except that when i run the final query to decrypt the data
It just comes up with null for each row. Even if i do a query to show me the rows that are not null
It's like it is saying yeah there is data here but I am only going to show you null instead of what I am supposed to decrypt.
Here is what I tried from start to finish
Create Certificate
TestCert
Encryption By Password = 'Password'
With Subject = 'SQLCert',
Expiry_Date = '12/01/2050';


declare @Test nvarchar(50)
set @Test='123456789'

insert into testenc (testencry)
Values
(encryptbyCert(Cert_ID('TestCert'),@Test ))


select convert (Nvarchar(50),
DecryptByCert(Cert_ID('TestCert'),
testencry,N'Password')) As Test
from testenc