Get the front wheels off the ground, start the engine, center the steering wheel. It should stay centered.

If it's not external drag maybe the steering box has a problme.

What if the alignment was done and the steering wheel was not centered
and then the "mechanic?) removed the steering wheel to correct.

Gotta be something in that steering box that centers the pitman arm or whatever it's called. The lever that connects the gear box to the steering linkage.