It would also be helpful to know how the OP is monitoring their scores. Perhaps their "before" score was from a month prior, meaning that any other number of different profile changes (like reported balance increases) could have played a role in the score drop seen with the new pull... so even if there wasn't an AoYA reset here yet with the new account reporting it's perfectly possible that it wasn't just the inquiry that dropped scores.
Also thinking out loud above, Amex usually just pulls EX to my knowledge, so if OP saw an equal drop in all 3B scores it was definitely the result of something outside of the inquiry such as balance increases, AoYA reset, etc.
