I bought 3 50+1 loot boxes during the anniversary sale and I have gotten a duplicate( Maybe from 2 legendary boxes, but 1 for sure from the most recent one). Just in case of a dupe bug, I opened the 50 normal anniversary loot crates first, then the legendary box. Then purchased 50+1 more, and then repeated 1 more time. The 2nd one probably had a duplicate but didn’t notice as I went to purchase the last batch. The last legendary loot crate I did notice and screenshotted. Support told me that they do not know which box I opened from to prove that this had happened. The last duplicate in the legendary loot crate was a bastion dune buggy.
Thanks.