authorize.net issue , payment not hitting their gateway

hi everyone, i got this wired issue lately on my latest zencart that it didn't seems to post the payment to their gateway ... i've been setup more than 4 zencart with authorize.net and none has issue before, called authorize.net and they told me they didn't even see the post ...

I am wondering where do i start to check to see if the request is indeed send out ( or if not, how to enable it )

thanks

config info below

I configured Authorize.net (SIM) module

Enable Authorize.net Module
True

Login ID
Starlines1

Transaction Key
**************** // this is set correctly

MD5 Hash
**** // this is also set

Transaction Mode
Production

Transaction Method
Credit Card

Authorization Type
Capture

Request CVV Number
False

Customer Notifications
False

Payment Zone
--none--

Set Order Status
default

Sort order of display.
0

Gateway Mode
offsite

Enable Database Storage
True

Debug Mode
Alerts Only

actually, it seems when i enable authorize AIM module in back , in the front it only shows

Payment Method Credit Card

no more field is displayed, so I guess the test purchase was actually send via the offline module ( which i just disabled now ) , not even send to the authorize.net

but why does AIM don't show any payment info ?

It seems you've probably got multiple modules enabled and you're having confusion as a result of seeing too many options on the screen when doing your testing.
Just enable the modules you need.
If you need to enable debug logging to find out more of what's happening, do that.