After importing a metabox, its field custom attributes are not editable

I exported a MB field group and imported it to a staging site. The custom attributes I had set for each field seem to have imported. BUT they do not appear when editing the metabox in the staging site.

Then I exported the field group from the dev site to see if maybe the custom attributes were lost/not imported. But I see them, just like in the original json file. Can you check if this is a bug, or otherwise advise why the custom attributes might not be displaying/editable when editing the metabox? Thank you

Json file contents below

{
    "$schema": "https://schemas.metabox.io/field-group.json",
    "autosave": false,
    "default_hidden": false,
    "fields": [
        {
            "name": "First Name",
            "id": "first_name",
            "type": "text",
            "required": true,
            "columns": 6,
            "limit_type": "character",
            "crm_field_id": "First_Name",
            "crm_field_type": "text"
        },
        {
            "name": "Last Name",
            "id": "last_name",
            "type": "text",
            "required": true,
            "columns": 6,
            "limit_type": "character",
            "crm_field_id": "Last_Name",
            "crm_field_type": "text"
        },
        {
            "name": "Email",
            "id": "email",
            "type": "email",
            "required": true,
            "crm_field_id": "Email",
            "crm_field_type": "text"
        },
        {
            "name": "Phone",
            "id": "phone",
            "type": "text",
            "limit_type": "character",
            "crm_field_id": "Phone",
            "crm_field_type": "phone"
        },
        {
            "id": "ref",
            "type": "hidden"
        }
    ],
    "id": "form-contact",
    "modified": 1767856129,
    "post_types": [
        "inquiry"
    ],
    "title": "Form - Basic Contact"
}