Go to ipad setting
Go to wi-fi and click on the wifi name
Click on the Configure IP. Take note of the IP Address
Change to Automatic and press Save.
After that, check your wifi if you can get IP address. If you are able to get, meaning another device is using the same IP in the network.
Tried to install an application call "Fing" from the Apple App store in the ipad.
After that, tried to scan the network and tried to locate which device is using the IP address. Then, change the IP address of the device.
Then, configure your ipad back to original IP address and try again.