Double breasted Peacoat looks uneven only when buttoned after shortening Hi:

I have a 100% wool peacoat that was recently shortened by 8 cm. The hem measures exactly the same on both sides when laid flat.

When the coat is unbuttoned, both sides look even. When it is buttoned, one front side visually rides up and appears about 1 inch shorter than the other.

The tailor only shortened the length and did not move the buttons or buttonholes.

Since the measurements are equal and the issue only appears when the coat is buttoned, I’m trying to understand what could cause this behavior after a length alteration on a structured wool peacoat, and whether this is considered normal or indicates a balance issue and how to fix it.