Updating to macOS Big Sur 11.2.3

My Mac mini (Late 2014) has Mac OS 11.1 installed. I am getting a system message to update to Big Sur 11.2.3. I've tried updating Normal mode, Safe mode, and even the restart with Option-Command-P-R

I am using Wired internet connection with 1Gb connection.

macOS Big Sur 11.2.3 11.2.3 — Restart Required

macOS Big Sur 11.2.3 provides important security updates and is recommended for all users.

For information on the security content of Apple software updates, please visit this website: https://support.apple.com/kb/HT201222

So I proceed.

3.2GB download and 1T drive with 400GB free.

and finally get

DOWNLOAD FAILED

An error occurred while downloading the selected updates. Please check your internet connection and try again.

So what are my options now? waste my time with a Genius bar visit?

I use a mac to avoid these MS like issues. and its depressing me, whats happened to Apple QA team?