Bevel modifier on a long object

I’m trying to round the edges of what will ultimately be a deck railing like this:

When I use the Bevel modifier i get a weird elongated bevel along the length of the beam like this:

Is there a way to avoid this?

The object has unapplied and non-uniform scale. Object mode, ctrl+A -> scale to apply.

How to avoid? Keep the scale as 1,1,1 and rotation as 0,0,0 while modeling and UV unwrapping. Scaling in object mode needs to be applied, and in edit mode there are no objects, so scaling the mesh/meshes (in this case) won’t affect the object.

Also would suggest not cropping the screenshots when asking questions. Cropping leaves information out, and the biggest mistake is to not prepare and provide an example .blend in the starting post. This time the cause is in the shot, assuming that fixes it, but that almost never happens since if the person asking the question would know to include it, wouldn’t need to ask questions in the first place.

Tutorial linked in my signature tells more about that.