minnoit

Sure.
I saved and now all is ok.
Now, the only Label and Placeholder that is hide is the one that I had manually added using Hooks in Woocommerce when I had problems with your plugin.
I think that’s another story and the problem is solved.
Thanks!

No.
I have installed “CodeStyling Localization” but I have not used it and it is disabled.
I have mentioned the translation because my problem is really evident and no others seems to have it.

I am not sure to remember but I think no: I had not make changes.
In Billing and Shipping sections I see default values for Requiered fields and some correctly translated strings for Labels and Placeholders.
Not all fields have value here.
Ex: for billing_first_name in Billing section I have
required = checked
Label = Nome
Placeholder = “” (void)

The labels and placeholders are correctly displayed on the site but they disappear if I enable the plugin.
There will be only one field with Label and Placeholder still visible:
it is the Order Comment on the right side of Checkout Page.
That field is not in Billing or Shipping sections of your plugin.

The problem may have something to do with translation?