Thanks for reporting this issue to us. I can confirm that this is very much a bug and a fix is on its way.
I will let you know once it has been deployed.
Our records show that order 1418265675 corresponds to 109-2396597-8688218 whereas order 1418266798 is for 103-5921525-3797067.
However, if I reverse engineer and try to find our orders associated to 103-5921525-3797067, I could find two orders (1418266798 and 1418265675-2). I believe that is the root cause of the issue. It is common to use the hyphen character in the order number if there is already that order number in the database. So for instance, orders 1418265675-2 and 1418265675 are two orders completely different.
On a bright side of things, with our upcoming shipworks integrations coupled with the fix, this sort of issues is sure to belong to the past.