This is a known issue:
[Issues updating Windows Defender (KB2267602 will not install)](https://learn.microsoft.com/en-us/answers/questions/953908/issues-updating-windows-defender-(kb2267602-will-n)
Run Windows Update Troubleshooter.
- Open Settings.
- Click on Update & Security.
- Click on Troubleshoot.
- Under the "Get up and running" section, select the Windows Update option.
- Click the Run the troubleshooter button