Sculpt/wifi_drv regression: no IP address

I updated to the 18.08 Genode release, built a Sculpt image, then booted it on my Dell Latitude 6430u laptop. I discovered that the WiFi driver, which worked in 18.05 (Sculpt TC) no longer works properly. In particular, the WiFi driver detects the access points and can connect to them, but doesn't get an IP address. I tried multiple access points, both my wireless router and my phone. With my phone, I used a clean lowercase alphabetic SSID ("bensphone"), to avoid any issues with problematic characters. I am using an Intel Ultimate-N 6300 wireless card.. Wired networking still works.