This is because you code was sent to you already multiple times in the past, quite a few times actually. Because the codes do not expire you expected to keep the code email. When you request again, you are in the bottom of the queue because I prioritize new users. I need to look up in a database each time your request. Is there a reason you cannot save your code on your computer? Personally I keep a local database of all the serial numbers for software I buy.
I get hundreds of code requests from people who didn’t buy the software at all. Daily I have to triage thru a list of requests from people who didn’t purchase the software. I put a system in place to prioritize people who fresh come from PayPal over having to manually look up people in a database of owners.
The code emails state
“Your Flexiauth Code is at the bottom of this message, please keep it in safe place in case you need it again”
You don’t need to change your email address in the code. The code works fine.
I’ll send you another code (again), please just save the code.
Also I tested the code you received last time on Nov 15, 2018 and it works.