I created a black and white image that is kind of tear drop shaped. Round at bottom, pointed at top.
I selected it.
I chose Brush->Capture Dab
I increase the brush size so the shape is obviously visible as I draw
No matter what I do with the pen - rotate, tilt, change direction - the brush remains pointy end up.
How do I get the dab to rotate as the brush moves around?
The mostly likely cause of this is the settings for "Ang Range" and "Ang Step". These controls are available in either the property bar (in the size flyout) or in the Angle Panel.
In order to find the Angle panel in Painter 2020 or newer, go to Window>Brush Control Panels> Brush Shape>Angle
With the angle panel open, set your "Ang Step" first, to something like 5 degrees. (Zero degrees tends to be overkill for most brushes and will likely be a bit slow when resized so i start with 5 and I rarely go below 1 degree). Now set your "Ang Range" to 360 degrees. Last, choose an expression such as "Direction" or "Bearing". Note that for "Rotate" to work you need a stylus with "Barrell rotation" support such as the Wacom Art Pen (https://estore.wacom.com/en-US/art-pen-kp701e2.html).
If this isn't the issue, we may need more detail about the settings with the brush that are preventing it from rotating.
If I try a different brush, say "Loaded Palette Knife" and set the brush expression to "Bearing" I do get a change in behavior. The brush angle seems to follow the direction my pen is moving.
To my knowledge, the PTZ-630's stylus supports pressure, tilt and bearing. In order to support Painter's "rotation" expression you would need to find and purchase a "6D Art Pen", it has a chisel tip and looks something like this: https://www.pinterest.ca/pin/830984568728308052/
What is the Painter expression you are using? For example, in addition to the angle settings I mentioned, make sure the expression is set to direction. Does the dab change direction as you paint strokes in different directions (horizontal, vertical, diagonal, etc.) How about Bearing? Does the dab change direction based on the angle of the stylus?
If neither of these are working, can you take a screen-shot of the following panels:
Because there are so many brush options in Painter, it may help to see exactly which brush and settings you are using to better troubleshoot it.