I've been having the same problem on android-x86_64-9.0-r2.iso (baremetal install/no VM, on asus laptop ux305fa). Found a workaround to get wifi back up and running:
Ctrl-Alt-F1 (to switch to console)
su (to get root)
ip link show wlan0 (shows wlan0 as DOWN)
ip link set wlan0 up
ip link show wlan0 (shows wlan0 as UP)
ping address-for-wifi-router (works now)
Ctrl-Alt-F7 (to switch back to GUI)
GUI at this point shows wifi is status is "connected" to my router, which I set up before with password and everything. Before I did the manual workaround, turning on the wifi slider button in the GUI caused an endless hang condition.
So the question is, why does wifi get hung up in the first place?
@colonal35 @panda9 @dbroadus2007 does my workaround have the desired effect for you?
UPDATE: in my case, after fixing as shown above, wifi came up automatically after next reboot.
UPDATE2:
I noticed that after applying my fix, my wireless mouse does not work anymore. Could it be that the orioginal problem occurs because ax86 gets confused when there are two wireless devices wifi+mouse (+bluetooth, but bt seems not affected). Strike the preceding. After next reboot the wireless mouse is working again. At least so far.