Templatefields are translated and stored correctly, but translations can't be set

When using translatable templatefields, it seems like the extension's javascript is unable to set all the individual fields to its translated counterpart. I ran into this issue while using a template that has 10 fields, including html and image fields.

As I was troubleshooting this, I noticed the translated fields are correctly set in the bolt_translation table. The JSON stored there, is parseable. But when field_locale.js tries to parse & set the fields, this exception is thrown:

TypeError: Cannot read property 'setData' of undefined(…)

When I debug the js, it breaks in this loop:

for (var field in val) {
    setValue('templatefields[' + field + ']', val[field]);
}

Removing my html field does not help either...

pages:
    name: Pages
    singular_name: Page
    class: \Bolt\Extension\Animal\Translate\Content\LocalizedContent
    fields:
        locale:
            type: locale
            group: content
        title:
            type: text
            class: large
            group: content
            required: true
            isTranslatable: true
        slug:
            type: slug
            uses: title
        template:
            isTranslatable: true
            type: templateselect
        seo:
            isTranslatable: true
            type: seo
            group: "SEO settings"
    default_status: published
    record_template: page_basic.twig

templatefields:
    page_home.twig:
        banner_heading:
          label: Heading
          type: text
          class: large
          required: true
        banner_content:
          label: Content
          type: html
          height: 300px
          required: true
        banner_cta_title:
          label: Call to action text
          type: text
          class: small
          required: true
        banner_image:
          label: Banner image
          type: image
        products_heading:
          label: Products listing heading
          type: text
          class: large
          required: true
        contentblock_heading:
          label: Right column heading
          type: text
          class: large
          required: true
        contentblock_content:
          label: Right column content
          type: html
          info: "The text that will be shown in the right column."
        contentblock_cta_title:
          label: Right column call to action text
          type: text
          class: small
          required: true
        contentblock_cta_url:
          label: Right column call to action URL
          type: text
          class: small
        references_heading:
          label: Reference listing heading
          type: text
          class: large
          required: true

Details

Relevant Bolt Version: 2.2.19-pl1
Install type: composer
PHP version: 7.0.0
Used webserver: Apache (MAMP)

BoltTranslate / Translate

Templatefields are translated and stored correctly, but translations can't be set #22

Details