Pass Dynamic Parameters to AWS Glue

I am trying to pass dynamic parameters to a glue job. I followed this question: AWS Glue Job Input Parameters

And configured my parameters like so:

I'm triggering the glue job with boto3 with the following code:

event = {
    '--ncoa': "True", 
    '--files': 'file.csv', 
    '--group_file': '3e93475d45b4ebecc9a09533ce57b1e7.csv', 
    '--client_slug': 'test', 
    '--slm_id': '12345'
}

glueClient.start_job_run(JobName='TriggerNCOA', Arguments=event)

and when I run this glue code:

args = getResolvedOptions(sys.argv, ['NCOA','Files','GroupFile','ClientSlug', 'SLMID'])

v_list=[{"ncoa":args['NCOA'],"files":args['Files'],"group_file":args['GroupFile'], "client_slug":args['ClientSlug'], "slm_id":args['SLMID']}]

print(v_list)

It just gives me 'a' for every value, not the values of the original event that I passed in from boto3. how do I fix that? Seems like im missing something very slight, but ive looked around and haven't found anything conclusive.