Cannot swap plan on Laravel/cashier-braintree while on trial

I'm trying to swap from a yearly plan to a monthly plan with Laravel/cashier-braintree^2.1 while on trial period, but it gives me error:

Argument 1 passed to Carbon\Carbon::instance() must be an instance of DateTime, null given, called in /home/vagrant/code/horsetap/vendor/laravel/cashier-braintree/src/Subscription.php on line 301

because billingPeriodEndDate is not yet set. As I read from docs it should be possible swapping plans while on trial.

via Chebli Mohamed