AlwaysEncrypted error when inserting via stored proc
So I figured out what I was doing wrong
AlwaysEncrypted requires the variables to be defined in line:

DECLARE @OPERATION_ID int = 4
DECLARE @PARAMETER_NAME varchar(100) = 'algorithm'
DECLARE @PARAMETER_METRIC varchar(100) = 'algorithm'
DECLARE @PARAMETER_VALUE varchar(100) = 'TestValue3'

INSERT INTO [dbo].[TOKEN_PARAMETER] (OPERATION_ID, PARAMETER_NAME,
PARAMETER_METRIC, PARAMETER_VALUE)
SELECT @OPERATION_ID,
       @PARAMETER_NAME,
       @PARAMETER_METRIC,
       @PARAMETER_VALUE


This allows for successful insert into the table.
When using a stored procedure you cannot use the same method to insert.

So in essence, there is nothing wrong with how to stored procedure works.
The application needs to change the way it populates the columns, using the same stored procedure

Please see below link for reference:

https://social.technet.microsoft.com/wiki/contents/articles/37979.working-with-the-always-encrypted-feature-in-sql-server-2016.aspx#Add_Data_to_Always_Encrypted_Column

Still waiting on applications team to come back with results but i'll mark the question as solved if this fixed the issue