Problems updating to IOS 17.4.1

I own an IPad Pro 12.9 2nd Gen (2018), presently running the latest version of IOS 16) According to the Apple website this particular IPad should be upgradable to the latest version (17.4.1) I received notification that the upgrade was available. (I have automatic upgrade deselected) I clicked on “download and install”, and entered my passcode. The time remaining appeared and the download finished. The “preparing update” appeared and the “installing update”. I waited for a very long time and the white apple logo never appeared. When I restarted the tablet it was still running IOS 16. The 17.4.1 download was located in the “settings/IPad storage”. Should I delete the 17.4.1 download and then re select “download and install” again. Approximately how long does it take for the process to be completed. (I understand that this would be affected by my WiFi connection, but are we talking hours?) Is it possible that I didn’t wait long enough for the update to fully take place? Any information or assistance would be greatly appreciated! Thanks in advance!