wifi not working on iPad Air 2 after upgrade. Tried all suggested fixes

Hello,

I suggest that you reach out to Apple for assistance.

Contact AppleCare

At first, mine was unable to connect to wifi, but then after about 10 tries, several hard restarts, and lots of patience, it finally connected and seems to hold the connection fine. However, my Air 2 is now painfully slow. I found this other discussion to help me with that issue: https://discussions.apple.com/thread/250667930