@flyforever The auto-spoilers on 146 aircraft are deactivated - look up on your overhead.
Standard practice on the 146 is on the short final have air-brake full open (there's actually a detent there on the real aircraft), then after touch-down the handle is manually brought full back into the lift spoiler detent.
This is to avoid having the very powerful lift spoilers opening and closing during a bounce.
It was refined on the Avro RJ which when auto-spoilers are activated behave more like you are used to.