Special characters not working with PHP 7.4

Hi,

I have a problem as follows and would appreciate any help you can offer:

When calling \DMore\ChromeDriver\ChromeDriver::setValue with a German special character such as a ß, I get an error: JSON: no input at position 0 (Behat\Mink\Exception\DriverException). When looking at the screenshot Behat took, it can be seen that the field is filled up to the special character and then stops (e.g. "Hauptstraße" becomes "Hauptstra").

Some specialty in the system I work on is that it uses ISO-8859 encoding, but the Behat feature files are encoded in UTF-8. Converting the string to ISO-8859 manually before passing didn't change the behavior though.

This only happens when using PHP 7.4, there is no problem with 7.2 or 7.3. This lib isn't tested yet against 7.4 or 8.0, so I'm not sure if you even support those versions officially.

Thanks for supporting!