So I did the bug fixes... whole file, not search & replace several times... but now when I checkout with a credit card I get
10002 Security error - Security header is not valid
It's also worth noting that I uninstall PP express & PP pro and reinstalled them. I researched the error and triple checked all of the credentials they are correct.
Transaction results in the security header error, here is the curl log
Code:
2023-01-20 05:51:45
-------------------
(live transaction) --> https://api-3t.paypal.com/nvp
Request Headers: 
Array
(
    [0] => Content-Type: text/namevalue
    [1] => X-VPS-Timeout: 90
    [2] => X-VPS-VIT-Client-Type: PHP/cURL
    [3] => X-VPS-VIT-Integration-Product: PHP::Zen Cart(R) - PayPal/NVP
    [4] => X-VPS-VIT-Integration-Version: 1.5.8
)
Request Parameters: {DoDirectPayment} 
Array
(
    [ACCT] => ************5340
    [AMT] => 15.98
    [BUTTONSOURCE] => ZenCart-DP_us
    [CARDISSUE] => 
    [CITY] => Woodbine
    [COUNTRYCODE] => US
    [CREDITCARDTYPE] => Visa
    [CUSTOM] => DP-13256-1674211905
    [CVV2] => ***
    [EMAIL] => [email protected]
    [EXPDATE] => 062023
    [FIRSTNAME] => xxxx
    [INVNUM] => 13256-1674211905-[xxx]
    [IPADDRESS] => xxx.xxx.xxx.xxx
    [ITEMAMT] => 5.25
    [LASTNAME] => xxxx
    [L_AMT0] => 5.25
    [L_NAME0] => Glass Shaker - Set of 2 [1868]
    [L_NUMBER0] => 742
    [L_QTY0] => 1
    [NOTIFYURL] => https://xxx/new/ipn_main_handler.php
    [PAYMENTACTION] => Sale
    [PAYMENTREQUEST_0_PAYMENTACTION] => Sale
    [PHONENUM] => xxx
    [SHIPPINGAMT] => 10.73
    [SHIPTOCITY] => xxxx
    [SHIPTOCOUNTRYCODE] => US
    [SHIPTONAME] => xxxx
    [SHIPTOSTATE] => GA
    [SHIPTOSTREET] => xxxx
    [SHIPTOZIP] => xxxx
    [STATE] => GA
    [STREET] => xxxx
    [ZIP] => xxxx
    [METHOD] => DoDirectPayment
    [CURRENCYCODE] => USD
    [USER] => xxxx_api1.xxxx.com
    [PWD] => ****************
    [VERSION] => 124.0
    [SIGNATURE] => ****************************************************tfB8
)
Response: 
Array
(
    [TIMESTAMP] => 2023-01-20T10:51:45Z
    [CORRELATIONID] => 4ce933a95d3bf
    [ACK] => Failure
    [VERSION] => 124.0
    [BUILD] => 56068150
    [L_ERRORCODE0] => 10002
    [L_SHORTMESSAGE0] => Security error
    [L_LONGMESSAGE0] => Security header is not valid
    [L_SEVERITYCODE0] => Error
    [CURL_ERRORS] => 
)
DoDirectPayment, Elapsed: 506ms -- Failure

TIMESTAMP=2023%2d01%2d20T10%3a51%3a45Z&CORRELATIONID=4ce933a95d3bf&ACK=Failure&VERSION=124%2e0&BUILD=56068150&L_ERRORCODE0=10002&L_SHORTMESSAGE0=Security%20error&L_LONGMESSAGE0=Security%20header%20is%20not%20valid&L_SEVERITYCODE0=Error&CURL_ERRORS=
new build 1.5.8 running the latest bootstrap & opc on PHP 7.3
Continued in next post as it was too long....

Thanks in advance
~Melanie