In version 2.9.11 when i add multiple repeaters it causes some unexpected issues. When i rollback elementor to 2.9.8 everything works just fine.

`
$this->start_controls_section(
'mc_test',
[
'label' => esc_html__('Test', 'mycar-core'),
'tab' => Controls_Manager::TAB_CONTENT

        ]
    );

    $repeater = new Repeater();
    $repeater->add_control(
        'text',
        [
            'label' => esc_html__('Text', 'mycar-core'),
            'type' => Controls_Manager::TEXT
        ]
    );
    $this->add_control(
        'test_1',
        [
            'label' => esc_html__('Test 1', 'mycar-core'),
            'type' => Controls_Manager::REPEATER,
            'fields' => $repeater->get_controls()
        ]
    );

    $repeater = new Repeater();
    $repeater->add_control(
        'text',
        [
            'label' => esc_html__('Text', 'mycar-core'),
            'type' => Controls_Manager::TEXT
        ]
    );
    $this->add_control(
        'test_2',
        [
            'label' => esc_html__('Test 1', 'mycar-core'),
            'type' => Controls_Manager::REPEATER,
            'fields' => $repeater->get_controls()
        ]
    );

    $this->end_controls_section();

`

After first time i add this widget all repeater controls work just fine. However after i refresh elementor edit page and try to add new item to one of these repeaters it doesn't nothing and console throw errors:

common.min.js?ver=2.9.11:2 TypeError: Cannot read property 'id' of undefined
at i.get (editor.min.js?ver=2.9.11:2)
at initialize (editor.min.js?ver=2.9.11:2)
at initialize (editor.min.js?ver=2.9.11:2)
at i.h.View (load-scripts.php?c=0&load[chunk_0]=jquery-core,jquery-migrate,underscore,shortcode,utils,backbone,wp-util,wp-backbone,media-models,moxiejs,plupload,wp-plupload,jqu&load[chunk_1]=ery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-sortable&ver=5.4.1:16)
at i.constructor (backbone.marionette.min.js?ver=2.4.5:22)
at i.constructor (backbone.marionette.min.js?ver=2.4.5:22)
at i.constructor (backbone.marionette.min.js?ver=2.4.5:23)
at i [as constructor] (load-scripts.php?c=0&load[chunk_0]=jquery-core,jquery-migrate,underscore,shortcode,utils,backbone,wp-util,wp-backbone,media-models,moxiejs,plupload,wp-plupload,jqu&load[chunk_1]=ery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-sortable&ver=5.4.1:16)
at i [as constructor] (load-scripts.php?c=0&load[chunk_0]=jquery-core,jquery-migrate,underscore,shortcode,utils,backbone,wp-util,wp-backbone,media-models,moxiejs,plupload,wp-plupload,jqu&load[chunk_1]=ery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-sortable&ver=5.4.1:16)
at new i (load-scripts.php?c=0&load[chunk_0]=jquery-core,jquery-migrate,underscore,shortcode,utils,backbone,wp-util,wp-backbone,media-models,moxiejs,plupload,wp-plupload,jqu&load[chunk_1]=ery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-sortable&ver=5.4.1:16)
consoleError @ common.min.js?ver=2.9.11:2
backbone.marionette.min.js?ver=2.4.5:22 Uncaught TypeError: Cannot read property 'cid' of undefined
at c.findByModel (backbone.marionette.min.js?ver=2.4.5:22)
at i.onButtonAddRowClick (editor.min.js?ver=2.9.11:31)
at HTMLDivElement.dispatch (load-scripts.php?c=0&load[chunk_0]=jquery-core,jquery-migrate,underscore,shortcode,utils,backbone,wp-util,wp-backbone,media-models,moxiejs,plupload,wp-plupload,jqu&load[chunk_1]=ery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-sortable&ver=5.4.1:3)
at HTMLDivElement.r.handle (load-scripts.php?c=0&load[chunk_0]=jquery-core,jquery-migrate,underscore,shortcode,utils,backbone,wp-util,wp-backbone,media-models,moxiejs,plupload,wp-plupload,jqu&load[chunk_1]=ery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-sortable&ver=5.4.1:3)

Specific steps to reproduce:

1. Add widget
2. Add at least one item to repeater
3. Save and refresh page
4. Add another item to repeater
5. no reaction and errors on console

Everything works just fine if there is just one repeater.