I had the same issue, there may be a better fix out there but I fixed it in ~15 minutes by doing a firmware recovery, the how-to guide is here: https://www.wifipineapple.com/pages/faq
Simplified:
Begin by downloading the factory firmware image for your device.
WiFi Pineapple NANO Factory Firmware Image - SHA256: 58b2401b790b484532351cfef3988e6d839682ae853bdb879c45f2e03e42c29e
Unplug the WiFi Pineapple completely from all power sources.
Press and hold the Reset button on the bottom of the Pineapple
Plug in the pineapple to your computer using the USB Y-cable
Keep holding the reset button for 10 seconds at least then release
The blue LED should remain solid (didn't for me)
Go to the adapter settings in network
(Windows 10)
Connection Icon in the bottom right
Network settings
Ethernet tab
Change adapter settings
Right click the Ethernet connection to the Pineapple and click properties
Click internet protocol version 4 and click properties
Click the "use this IP address radio button and set the IP address to 192.168.1.2
Set the subnet mask to 255.255.255.0 then click okay
From your browser type http://192.168.1.1in the URL bar and press enter
Click Choose File and select the factory firmware image (This may happen automatically)
Click Update Firmware
This process can take several minutes, when I did this update there was no redirect after the update had finished so I left it to run for ~15 minutes to be safe however the Pineapple will restart after the update is complete so keep an eye on it.
Reset the the WiFi Pineapple Ethernet interface back to 172.16.42.42 with submask 255.255.255.0
hope this helps,
if you or anyone else wants to learn more about the pineapple feel free to PM me, I'm fairly new to this and am looking for others that want to get up to speed on this kit with me.