Notice: Undefined index: expires_at in /var/www/html/storeko/vendor/compropago/magento2/Model/Cash.php

[SantiagoMenelao]

Buenas!
Al efectuar pago via oxxo en web recibo el siguiente error
Notice: Undefined index: expires_at in /var/www/html/storeko/vendor/compropago/magento2/Model/Cash.php on line 353

trace
trace: "#0 /var/www/html/storeko/vendor/magento/framework/Interception/Interceptor.php(58): Magento\Checkout\Model\PaymentInformationManagement->savePaymentInformationAndPlaceOrder(2, Object(Magento\Quote\Model\Quote\Payment\Interceptor), Object(Magento\Quote\Model\Quote\Address))↵#1 /var/www/html/storeko/vendor/magento/framework/Interception/Interceptor.php(138): Magento\Checkout\Model\PaymentInformationManagement\Interceptor->___callParent('savePaymentInfo...', Array)↵#2 /var/www/html/storeko/vendor/magento/framework/Interception/Interceptor.php(153): Magento\Checkout\Model\PaymentInformationManagement\Interceptor->Magento\Framework\Interception\{closure}(2, Object(Magento\Quote\Model\Quote\Payment\Interceptor), Object(Magento\Quote\Model\Quote\Address))↵#3 /var/www/html/storeko/generated/code/Magento/Checkout/Model/PaymentInformationManagement/Interceptor.php(26): Magento\Checkout\Model\PaymentInformationManagement\Interceptor->___callPlugins('savePaymentInfo...', Array, Array)↵#4 [internal function]: Magento\Checkout\Model\PaymentInformationManagement\Interceptor->savePaymentInformationAndPlaceOrder(2, Object(Magento\Quote\Model\Quote\Payment\Interceptor), Object(Magento\Quote\Model\Quote\Address))↵#5 /var/www/html/storeko/vendor/magento/module-webapi/Controller/Rest/SynchronousRequestProcessor.php(95): call_user_func_array(Array, Array)↵#6 /var/www/html/storeko/vendor/magento/module-webapi/Controller/Rest.php(244): Magento\Webapi\Controller\Rest\SynchronousRequestProcessor->process(Object(Magento\Framework\Webapi\Rest\Request\Proxy))↵#7 /var/www/html/storeko/vendor/magento/framework/Interception/Interceptor.php(58): Magento\Webapi\Controller\Rest->dispatch(Object(Magento\Framework\App\Request\Http))↵#8 /var/www/html/storeko/vendor/magento/framework/Interception/Interceptor.php(138): Magento\Webapi\Controller\Rest\Interceptor->___callParent('dispatch', Array)↵#9 /var/www/html/storeko/vendor/magento/framework/Interception/Interceptor.php(153): Magento\Webapi\Controller\Rest\Interceptor->Magento\Framework\Interception\{closure}(Object(Magento\Framework\App\Request\Http))↵#10 /var/www/html/storeko/generated/code/Magento/Webapi/Controller/Rest/Interceptor.php(26): Magento\Webapi\Controller\Rest\Interceptor->___callPlugins('dispatch', Array, Array)↵#11 /var/www/html/storeko/vendor/magento/framework/App/Http.php(135): Magento\Webapi\Controller\Rest\Interceptor->dispatch(Object(Magento\Framework\App\Request\Http))↵#12 /var/www/html/storeko/generated/code/Magento/Framework/App/Http/Interceptor.php(24): Magento\Framework\App\Http->launch()↵#13 /var/www/html/storeko/vendor/magento/framework/App/Bootstrap.php(257): Magento\Framework\App\Http\Interceptor->launch()↵#14 /var/www/html/storeko/index.php(39): Magento\Framework\App\Bootstrap->run(Object(Magento\Framework\App\Http\Interceptor))↵#15 {main}"