BevelButton.LockTop

From Xojo Documentation

Property (As Boolean )
aBevelButton.LockTop = newBooleanValue
or
BooleanValue = aBevelButton.LockTop

Supported for all project types and targets.

Determines whether the top edge of the control should stay at a set distance from the top edge of the owning window. LockTop has no effect unless LockBottom is True.