This plugin breaks esc_attr

From source:
public function change_button_text($safe_text, $text) {
return str_replace( __(“Insert into Post”,”cvti”), __(“Use this image”,”cvti”), $text);
}

esc_attrs: https://developer.www.ads-software.com/reference/functions/esc_attr/

So you are applying changes to original text.
I think you need to change $text to $safe_text.