My current lines 955-957 just to make sure nothing fatfingered
Code:
  $transactionRequestType->setTransactionType("authCaptureTransaction");
            trigger_error($order->info['total']);             
            $transactionRequestType->setAmount(number_format($order->info['total'], 2, '.', ''));
/includes/modules/payment/authorizenet_cim.php

I didn't expect the error to change.

First pass through checkout
Use saved card on file
Error 5
Second pass
Session expired and wiped out cart
rebuild cart
checkout using a different card
Error 33 now

MyDebug
Code:
[27-Apr-2020 13:46:34 America/Los_Angeles] Request URI: /index.php?main_page=checkout_process, IP address: 98.146.164.107
#1  trigger_error() called at [/home/chainwea/public_html/includes/modules/payment/authorizenet_cim.php:956]
#2  authorizenet_cim->chargeCustomerProfile() called at [/home/chainwea/public_html/includes/modules/payment/authorizenet_cim.php:325]
#3  authorizenet_cim->before_process() called at [/home/chainwea/public_html/includes/classes/payment.php:246]
#4  payment->before_process() called at [/home/chainwea/public_html/includes/modules/checkout_process.php:92]
#5  require(/home/chainwea/public_html/includes/modules/checkout_process.php) called at [/home/chainwea/public_html/includes/modules/pages/checkout_process/header_php.php:14]
#6  require(/home/chainwea/public_html/includes/modules/pages/checkout_process/header_php.php) called at [/home/chainwea/public_html/index.php:36]
--> PHP Notice: 27.0339 in /home/chainwea/public_html/includes/modules/payment/authorizenet_cim.php on line 956.

[27-Apr-2020 13:46:34 America/Los_Angeles] Request URI: /index.php?main_page=checkout_process, IP address: 98.146.164.107
#1  trigger_error() called at [/home/chainwea/public_html/includes/modules/payment/authorizenet_cim.php:447]
#2  authorizenet_cim->logError() called at [/home/chainwea/public_html/includes/modules/payment/authorizenet_cim.php:1023]
#3  authorizenet_cim->chargeCustomerProfile() called at [/home/chainwea/public_html/includes/modules/payment/authorizenet_cim.php:325]
#4  authorizenet_cim->before_process() called at [/home/chainwea/public_html/includes/classes/payment.php:246]
#5  payment->before_process() called at [/home/chainwea/public_html/includes/modules/checkout_process.php:92]
#6  require(/home/chainwea/public_html/includes/modules/checkout_process.php) called at [/home/chainwea/public_html/includes/modules/pages/checkout_process/header_php.php:14]
#7  require(/home/chainwea/public_html/includes/modules/pages/checkout_process/header_php.php) called at [/home/chainwea/public_html/index.php:36]
--> PHP Notice: Transaction Failed 
 Error code  : 33
 Error message : Card Code is required.
 in /home/chainwea/public_html/includes/modules/payment/authorizenet_cim.php on line 447.