One Step Checkout 4.5.5 / pp+ 1.5.1 / patch issue : infinite loop in ajax refreshes

payment.phtml

<?php
/**
 *
 * NOTICE OF LICENSE
 *
 * This source file is subject to the Open Software License (OSL 3.0)
 * that is bundled with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://opensource.org/licenses/osl-3.0.php
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@magentocommerce.com and you will be sent a copy immediately.
 *
 * Created on 02.03.2015
 * Author Robert Hillebrand - hillebrand@i-ways.de - i-ways sales solutions GmbH
 * Copyright i-ways sales solutions GmbH © 2015. All Rights Reserved.
 * License http://opensource.org/licenses/osl-3.0.php Open Software License (OSL 3.0)
 *
 */
$paymentExperience = $this->getPaymentEperience();
if ($paymentExperience) :
    ?>
    <div id="ppplus"></div>
    <script type="text/javascript">
        if(typeof payment == 'undefined') {
            var payment = {};
        }

        function selectMethod(code) {
            // One Step Checkout support Madis 7 may 2018
            // issue: infinite loop when invalid coupon is entered. if already checked, do not simulate click.
            if ( ! document.getElementById('p_method_' + code).checked)
            	 document.getElementById('p_method_' + code).click();
        }
        
        window.externMethodEnabled = false;
        window.startPPP = function () {
            if(typeof window.thirdPartyObject == 'undefined') {
                window.thirdPartyObject = {<?php echo $this->getThirdPartyJsonObject(); ?>};
                window.thirdPartyMethodObject = {<?php echo $this->getThirdPartyMethodJsonObject(); ?>};
            }
            document.cookie = 'paypalplus_session=; Path=/checkout/onepage; Expires=Thu, 01 Jan 1970 00:00:01 GMT;';
            document.cookie = 'paypalplus_session=; Path=/checkout; Expires=Thu, 01 Jan 1970 00:00:01 GMT;';
            document.cookie = 'paypalplus_session=; Path=/firecheckout; Expires=Thu, 01 Jan 1970 00:00:01 GMT;';
            document.cookie = 'paypalplus_session=; Path=/onestepcheckout; Expires=Thu, 01 Jan 1970 00:00:01 GMT;';

            selectMethod('iways_paypalplus_payment');
            window.ppp = PAYPAL.apps.PPP(
                {
                    approvalUrl: "<?php echo $paymentExperience; ?>",
                    placeholder: "ppplus",
                    mode: "<?php echo Mage::getStoreConfig('iways_paypalplus/api/mode'); ?>",
                    useraction:"commit",
                    buttonLocation:"outside",
                    <?php if($this->isPuiSandboxMode()) : ?>
                    showPuiOnSandbox: true,
                    <?php endif; ?>
                    country:"<?php echo $this->getCountryId(); ?>",
                    language:"<?php echo $this->getLanguage(); ?>",
                    onContinue: function () {
                        payment.save()
                    },
                    onThirdPartyPaymentMethodSelected:function (data) {
                        this.lastCall = 'onThirdPartyPaymentMethodSelected';
                        selectMethod(window.thirdPartyObject[data.thirdPartyPaymentMethod]);
                    },
                    enableContinue: function (data) {
                        if(this.lastCall != 'onThirdPartyPaymentMethodSelected') {
                            selectMethod('iways_paypalplus_payment');
                        }
                        this.lastCall = 'enableContinue';
                        try {
                            if($$('#payment-buttons-container > button').length > 0) {
                                $$('#payment-buttons-container > button')[0].enable();
                            }
                            if($('onestepcheckout-place-order') != null) {
                                $('onestepcheckout-place-order').enable();
                            }
                            if($$('#review-buttons-container > button').length > 0) {
                                $$('#review-buttons-container > button')[0].enable();
                            }
                            if($('onestepcheckout-button-place-order') != null) {
                                $('onestepcheckout-button-place-order').enable();
                            }
                        }catch (e) {
                            console.log(e);
                        }
                    },
                    disableContinue: function (data) {
                        if(!window.externMethodEnabled) {
                            try {
                                if($$('#payment-buttons-container > button').length > 0) {
                                    $$('#payment-buttons-container > button')[0].disable();
                                }
                                if($('onestepcheckout-place-order') != null) {
                                    $('onestepcheckout-place-order').disable();
                                }
                                if($$('#review-buttons-container > button').length > 0) {
                                    $$('#review-buttons-container > button')[0].disable();
                                }
                                if($('onestepcheckout-button-place-order') != null) {
                                    $('onestepcheckout-button-place-order').disable();
                                }
                            }catch (e) {
                                console.log(e);
                            }
                        }
                    },
                    <?php echo $this->getThirdPartyMethods(); ?>
                });
        }
        window.startPPP();
        function checkStep() {
            try {
                if(typeof window.checkout != 'undefined' && typeof window.lastStep == 'undefined') {
                    window.lastStep = window.checkout.accordion.currentSection;
                }
                if (typeof window.lastStep != 'undefined' && window.lastStep != window.checkout.accordion.currentSection) {
                    window.lastStep = checkout.accordion.currentSection;
                    if (checkout.accordion.currentSection == "opc-payment") {
                        window.startPPP();
                    }
                }
            } catch(e) {
            }
        }
        window.setInterval(checkStep, 1000);

    </script>
<?php endif; ?>