See testcase at https://codepen.io/jnurthen/live/PoNzgdq - note my system is running in US English

    <div lang="fr">
      <button>en français</button>
      <label>Prénom<input type="text"></label>
    </div>

The button reads correctly with the accessible name in French and the role in english
The Static text on the screen reads correctly in French
but the input field reads as "preeenom edit text" (i.e. with Prénom read with the English voice) - the accessible name should be read in the HTML language not the OS language.