The 64-bit client can consume CPU during initial indexing. Allow it to finish. If it persists:

Microsoft has shifted its strategy. As of 2021, on 64-bit systems by default for new installations. However, if you upgraded from an older version of Windows, you might still be running the 32-bit client.

: Click the white or blue cloud icon in your taskbar notification area to log in with your Microsoft account.

: 64-bit applications can access more system memory (RAM) and processing power than 32-bit versions.