I just checked it, and logged on straight away.
Have you tried closing it in the multitask bar and restarting it? That will force it to start from scratch. Here's the method.
Four finger swipe up the screen to reveal the multitask bar.
Long press on any app in the list until a minus sign appears.
Touch the minus sign on each app to close it.
Four finger swipe down the screen to return to normal.
If this doesn't work, maybe try a different network, a coffee shop or something.
Other things to try:
Reboot your router
Hard reset your iPad
Reset network settings
I don't want to recommend this, especially if everything else is working, but if all else fails you could try changing your DNS settings to Google's public server. That has worked for some members who have had network issues.
Sent from my iPad using iPF