Looks obvious to me that the UVs are oriented differently. Take a look at the original UVs and compare. It’s probably the “smart” of SmartUV project that is kicking in. I would add a seam, reset one quad and follow quads for the rest. Then turn on “about 2D cursor” and activate “constrain to image bounds”, select everything and scale so that it fits the space. This gives you a perfect UV space for math operations, but may not be suitable for painting on.
Cylinder projection from front view might also work, but you may have to reposition/scale the UV island.
If I add a cylinder with create UVs enabled (no caps), I also get a perfect UV layout for this purpose. No unwrapping required.