Widgets are not translatable by default in wpml.
To make them translatable in wpml, you have to write some integration schema, and put it into the wpml options.
Example of this schema:
<wpml-config>
<elementor-widgets>
<!-- widget name used in Unlimited Elements prepended with "ucaddon_" -->
<widget name="ucaddon_widget_name">
<!-- add single fields here
type="Description of field in WPML"
editor_type="Type of field"
textfield = "LINE"
textarea = "AREA"
url = "LINK" (or "LINE")
-->
<field type="Headline" editor_type="LINE">headline_field</field>
<field type="Content" editor_type="AREA">content_field</field>
<!-- items are listed as "uc_items" -->
<fields-in-item items_of="uc_items">
<field type="Title" editor_type="LINE">item_title_field</field>
<field type="Subtitle" editor_type="LINE">item_subtitle_field</field>
<field type="Description" editor_type="AREA">item_description_field</field>
<field type="Button Text" editor_type="LINE">item_button_field</field>
<field type="Button URL" editor_type="LINK">item_button_link_field</field>
</fields-in-item>
</widget>
<!-- add more widgets here
<widget name="ucaddon_widget_name2">
...
</widget>
-->
</elementor-widgets>
</wpml-config>
