Please understand that the Apple Support Community is a user-to-user technical forum. Contributors here are all end-users, just like you. Other than the site Moderators, Apple neither monitor nor participate here. As such, if you hope to reach Apple Support or Engineering teams via these forums, you will be disappointed.
Should you need to do so, you can contact the Support Team using the Support link at top-right or bottom-left of this page. Your comprehensive notes and analysis may be helpful.
You can also initiate and manage your support cases from Apple devices using the excellent Apple Support App. If not already installed, the App can be downloaded from the App Store:
https://apps.apple.com/app/apple-support/id1130498044
For troubleshooting your WiFi connection issue, start here:
If your iPhone, iPad, or iPod touch won’t connect to a Wi-Fi network - Apple Support
…and here:
Recommended settings for Wi-Fi routers and access points - Apple Support
If your WiFi has been set-up according to Apple’s recommended settings, WiFi and Internet connection difficulties are usually an indication that your device does not have a routable IP Address - your IP Address usually being assigned by DHCP. When this occurs, your iPad may only have a self-assigned link-local IP address that begins 169.254.x.x.
If you have a VPN App or profiles installed, or a security App such as Norton, these may be interfering with your device's network stack. Where applicable, the resolution is usually simple; if installed, you may need to [at least temporarily] disable or completely remove the Security App and/or VPN.
If you continue to have difficulties, check to see if your iPad is using the WiFi Private Address feature. This feature is intended to provide additional privacy and security when using “public” (untrusted) WiFi networks.
Settings > WiFi > [Your WiFi Network / SSID] - tap the “i” icon - Private Address
The Private Address feature is largely unnecessary for private WiFi networks; if enabled, Private Addressing can cause issues if specific MAC addresses are expected. You may need to disable this feature - and can be enabled or disabled for each individual network.
Use private Wi-Fi addresses in iOS 14, iPadOS 14, and watchOS 7 - Apple Support
