It is not advised to have two resident antiviruses at the same time, which is why Windows disables Defender when a 3rd party AV is installed (to avoid potential conflict).
It is like two dogs fighting over one bone. So it looks like MBAM is intercepting it otherwise you would be getting an avast alert.
It does look like the same thing is happening, so you need to wait for a response at malwarebytes forum so a qualified malware removal specialist can advise you.