Lazy Approval assigning wrong outcome.

I have a workflow that makes use of the "Assign as Task Process" action and I've enabled Lazy Approval. The issue is that for some users, they reply to the task email with the word "Approved" (on a line at the top by itself, as instructed), but the workflow resolves it as "Rejected" and follows down that branch of the task. 

Hopefully someone else has experienced this and can explain how to prevent it.

I've attached some screenshots of the configuration below, along with a redacted screenshot of the email where the user replied with the word "Approved" and the final outcome of the actual task in SharePoint.