Bent rail, disappointed with result - Presma AR-15 Super Light M-LOK Series Free Float Handguards

Had a gunsmith install the barrel, barrel nut and rail on my AR build. The gunsmith was puzzled. He checked the bore and confirmed my Rosco purebred series barrel was true and straight, he lapped the BCM upper square and true, tried the barrel nut both ways as its threaded on both ends and still he couldn’t figure out why the barrel was closer to the right of the rail. I checked the barrel, bore sighted twice, confirmed everything was square and straight. Turns out the presma rail is bent. Still waiting for optics planet to send a replacement.