Yes, sorry.

[21-Sep-2020 19:42:37 UTC] Request URI: /opm/index.php?main_page=checkout_process, IP address: 207.228.78.224
#1 trigger_error() called at [/home/kwadmin1/public_html/opm/includes/classes/db/mysql/query_factory.php:170]
#2 queryFactory->show_error() called at [/home/kwadmin1/public_html/opm/includes/classes/db/mysql/query_factory.php:142]
#3 queryFactory->set_error() called at [/home/kwadmin1/public_html/opm/includes/classes/db/mysql/query_factory.php:269]
#4 queryFactory->Execute() called at [/home/kwadmin1/public_html/opm/includes/functions/database.php:44]
#5 zen_db_perform() called at [/home/kwadmin1/public_html/opm/includes/modules/payment/paypalwpp.php:544]
#6 paypalwpp->after_process() called at [/home/kwadmin1/public_html/opm/includes/classes/payment.php:261]
#7 payment->after_process() called at [/home/kwadmin1/public_html/opm/includes/modules/pages/checkout_process/header_php.php:17]
#8 require(/home/kwadmin1/public_html/opm/includes/modules/pages/checkout_process/header_php.php) called at [/home/kwadmin1/public_html/opm/index.php:35]
--> PHP Fatal error: 1366:Incorrect decimal value: '14.95 USD' for column 'settle_amount' at row 1 :: INSERT INTO paypal (order_id, txn_ty
etc...

And yes, that line 536 in paypalwpp.php is exactly as your example.