Payer Authentication disabled.

Hi there
Since v3.1 this plugin has become useless.
Firstly, having on charge fees activated for woocommerce payments results in Messages”:[“(unprocessable) Incorrect Expected Oncharged Fee.”],”console”:”credit_card_iframes”,”Status”:422
Secondly, when on charge is disabled customers can not pay as the message displayed is “ayer Authentication disabled. Cannot start payer authentication.”
Pretty disappointing as it was working perfectly in v3.0