Internet connection problems and Downgrading from ipados 15

Is WiFi/Internet connectivity entirely absent, or intermittent? More information about the symptoms that you observe may be helpful in identifying the root cause.

If you have a VPN App or profiles installed, or a security App such as Norton, these may be interfering with DHCP and preventing your device from obtaining a valid IP Address for your iPhone hotspot - or the WiFi network to which you are attempting to connect. The resolution is usually simple; if installed, you may only need to temporarily disable or remove the Security App and/or VPN.

DHCP is frequently used to automatically obtain an IP Address. Until your iPad has a valid IP Address to connect to your network, you will not have an internet connection. Disabling or removing VPN and/or the offending security App should allow DHCP to operate normally - allowing connection to your network and the internet.

If this resolves your issue, the VPN and/or security App can be reinstated after the connectivity problem has been resolved.

Having updated to iPadOS15 from iPadOS14, if you have not already done so, a forced-restart is recommended - as this will usually clear any post-update issues:

• On an iPad with a Home button: Press and hold the top button and the Home button at the same time. When the Apple logo appears, release both buttons.
• On other iPad models: Press and quickly release the volume up button, press and quickly release the volume down button, then press and hold the top button. When the Apple logo appears, release the button.

Downgrade to an earlier version of iPadOS is not possible. All System Updates are digitally signed by Apple - and can only be installed whilst the digital signatures remain valid. After release of a new iOS/iPadOS version, the immediately preceding version continues to be digitally signed by Apple for a few days, after which Apple will revoke the digital certificate with which the earlier version is signed.

At present, only iPadOS 15.2 is available for re-installation.

As described, your iPad is still using DHCP to obtain its assigned IP Address from your WiFi Router. Assigning a permanent DHCP lease in your router configuration, for your iPad (or any device) is not the same as assigning a static IP Address in your iPad settings.

As configured, while you may have a non-expiring DHCP lease, your iPad will still be regularly refreshing its IP Address assignment from your router. As a diagnostic exercise, you would be well advised to manually set a static IP Address, subnet mask, Router IP and DNS addresses in iPad settings - as this will remove DHCP from the equation.

A further potential source of issues is WiFi interference - despite other devices appearing to operate without issue. Presumably your WiFi Router is dual-band - able to support both 2.4GHz and 5GHz connections. Are both bands using the same WiFi Network Name (SSID) - or are you able to configure your router to use a different network name for each WiFi band? If you are able, as a diagnostic tool, try setting different WiFi Network Names for 2.4GHz and 5GHz bands; if not, temporarily disable the 2.4GHz band in your router settings. The objective here is to force your iPad to use the less congested (and less prone to interference 5GHz band).

Finding the permanent solution first needs an understanding of the problem - hence the diagnostic exercises that I have suggested. When we fully understand the cause, a solution can be identified.

Consider that if you were to visit your doctor with a health issue, he (or she) may need to perform some route tests before giving a diagnosis of your complaint. When you understand the illness, it may be possible to prescribe a treatment or remedy.