Woocomm.: create acct does not display fields for username and password

Hi team, Just submitted the phone field thread, but now opening up a new thread as I've got a different topic on Woocommerce, which I really hope you can help me with. It appears to be theme-specific, as it doesn't occur if I use the default wordpress theme (twenty-sixteen). Here's the problem: New customers can register at the checkout page. The checkbox for this does indeed appear. However, once I tick it, nothing happens: no fields appear for entering username and/or password. Screenshot: http://prntscr.com/c7bjkk As you can see, there's just a blank space. I've made the columns a little longer to make sure the fields weren't hidden by the order-overview below it. This is how it looks when using Twenty-sixteen: http://prntscr.com/c7bgxw Here the fields are clearly there. While searching the internet, I came across the following regarding this problem (admittedly, another theme, but perhaps helpful nonetheless): https://wordpress.org/support/topic/not-working-on-register-form?replies=32 .... "Found the issue. WooCommerce in their infinite wisdom uses 2 different systems for the registration, one for checkout, one for the My Account page. The My Account page just uses the built in WordPress registration hooks, which works if the normal [*insert theme-name*] Registration validation is turned on, but doesn't work if just the WooCommerce one is. Curses! Anyway, patches coming for .... " made me think that this may be happening in Gridalicious Pro as well. In case you'd like to check on my site (nothing else there but WordPress, Gridalicious Pro and Woocommerce so far) : www.gewoonmooigewicht.nl I've added a test-shop (winkel) from where you can add sth to your cart and then proceed to checkout, to view this problem. Could you please have a look at this? Thank you so much! Of course I don't know how they solved it (doesn't say there), but practically thinking, both instances should just check the woocommerce settings for registration? After testing, I can add that the fields don't show up either if I've got the general WordPress registration enabled in Gridalicious Pro. (I'd love to keep these disabled, though). Kind regards, Henriët