iPad Air 2 stuck on Checking for update ...?

I'm trying to update my iPad Air 2 running iOS 9.3.5 to iOS 11 over the air. It says there's an update available ( red circled "1" shows in Software Update under Settings > General) but it is stuck on Checking For Update ... Ive plugged it in, charged it to 100%, locked it, etc. Nothing seems to happen.

FYI: About a month ago, it downloaded the update automatically but I deleted the file within the Manage Storage setting because it was taking up space. Maybe I confused it?) Now that I want/need iOS 11 have over 54 GB of space available on my iPad, nothing is happening.

I can't update via iTunes as that is not an option at this current time.

Any help? Thanks!