Hello and welcome to the forum.
We'll probably need some additional info as to what "computer" actually means.
AND
Exactly what the problem is. IF I understand correctly, when you shut down the computer normally the computer spontaneously starts back up again without you actually doing anything??? It doesn't stay shut down??
I can only say that....
The last time this happened to me was on a friends computer and after trying everything I could think of including a wipe and clean install, I figured out it was a hardware issue and after some aggravating troubleshooting it turned out to be that his desktop computer had a PCIe 4x wireless add-on card installed.
When I removed it physically from the computer, the problem went away. The computer would shut down and stay shut down.
I had him replace it with a
https://smile.amazon.com/gp/product...3-992f-4bde-81b0-de270e0ead5a&pf_rd_i=desktop
He hasn't had any trouble since.