i'll try again...
"Is it possible that these could be manufactured out of round?"
YES!
is your crank a one piece, "Ashtabula" type?
like this one?
https://www.ebay.com/itm/25609923033...029e9154cf723a
if so, it is, almost certainly, Manufactured Out of Round...
almost ALL of them are manufactured out of round.
and they also BEND when the bikes get jumped and /or Crash hard.
Not that BMX bikes ever get Abused then Sold....
you may want to try Re-Centering the Chain ring a few times, testing it each time.. is there any slop to allow a minor re-centering?
the "tight spot" will happen when the Ring is out towards the Front of the bike.. tap it back when it's at the "tight spot".. Place a chunk of wood over the teeth with CHAIN IN PLACE, then whack the wood with a hammer... see if it moved.
btw... the rear gear/freewheels and hubs are also out of round...they will cause extra-tight and loose spots that don't happen in exact rhythm with the crank turnings... been there a million times, and probably a few more this weekend,... sigh.