BubblyDruid is entirely right. the FBW “mod” is getting as close as possible to the real Airbus A20N specs and performances. When you are litterally at 1kt from overspeeding, the plane would just not “dive” because it is unsafe. You would indeed as he suggest have to either throttle down manually, or set in “climb” mode, and reduce speed on your AP, before even considering to lower the nose.