I am unable to update my Mac mini M1 to the latest update 11.2.3

Are you using an Administrator account because sometimes there can be issues while updating from an account that doesn’t have administrator privileges. If you are you might want to try contacting Apple Support here. https://support.apple.com/contact

Have you tried checking if you have enough available storage? If you have enough storage, then you might want to try to shut it down and restart it. If the problem still persists it might be your internet connection. If you have a weak connection then your Mac might have trouble installing the update.

Suggest - restart Router and then Shutdown Computer and connect via Ethernet connection. Restart computer in Safe Mode - Shift - Key immediately at startup. It does a Repair Disk, clears cache files and load only Apple Software - load slowly - Normal. Once in Open Apple Apps Store and find Big Sur and download. Try not to let computer go to sleep mode or Screen Save to activate. Be patient as one knows it Big Sur is 12.18 GB size. There are often periods where it seems to pause the download , normal be patient as countdown clock may say 15 minutes but in Real Time could be 30 - 45 minutes. This can and will happen several time in the process. If all goes well. it will successfully download and attempt to Launch. Do NOT allow it to start - Quist the Installer. Check Applications Folder for new App called Install Bug Sur. Make a copy to External Drive - future usage. Now, restart again in Safe Mode - then launch the Installer.