Hi,
Could you open PowerShell through
start powershell.exe command in Command Prompt
or find it in search box?
If you could open it, please try to remove the PowerShell form the list by right click the icon as following screenshot. Then try to re-pin it to Start Menu.

Or please try to create shortcut from %SystemRoot%\system32\WindowsPowerShell\v1.0 folder.
Please remember to mark the replies as answers if they help.
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