JavaScript error while generating webp images from the settings page

[Screenfeed]

TypeError: item is undefined
https://example.com/wp-content/plugins/imagify/assets/js/options.js line 778

imagify-plugin/assets/js/options.js

Lines 768 to 783 in d81c3c2

	if ( ! this.queue.length && ! this.processingQueue.length ) {
	return;
	}
	// Optimize the files.
	$.each( this.queue, function ( i, item ) {
	if ( _this.processingQueue.length >= imagifyOptions.bulk.bufferSize ) {
	return false;
	}
	$.each( item.mediaIDs, function () {
	_this.processMedia( {
	context: item.context,
	mediaID: item.mediaIDs.shift(),
	optimizeURL: item.optimizeURL
	} );

The loop finds a second item in this.queue while there is actually only one. I couldn't find the reason of this error but this simple test prevents the issue:

// Optimize the files.
$.each( this.queue, function ( i, item ) {
	if ( ! item ) {
		return true;
	}
	if ( _this.processingQueue.length >= imagifyOptions.bulk.bufferSize ) {
		return false;
	}

Browser: Firefox Developer Edition 77.0b2.