MsMpEng.exe is still running even though I have other antivirus installed

[Calllum9895]

Antimalware service executable was using up as much as %50 of my cpu so I decided to try installing Malwarebytes. I did that, and when I go to windows security setting it says the Malwarebytes is on and windows defender is disabled, and yet when I boot my computer Antimalware service executable is still running and using large amounts of my cpu. Why is it still running? And is there a way I can turn it off?

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