https://wccftech.com/bethesda-remove-duped-items-fallout-76/

Bethesda announced that later today, during the server maintenance, all duplicate items obtained through a known exploit will be removed from Fallout 76. Players have been asking this for quite some time and finally, the developers have agreed this was needed.

We’re planning to bring Fallout 76 offline for maintenance around 9:00 a.m. EST on February 14, and anticipate that downtime will last several hours. During this time, we’re planning to remove items that have been created through duplication exploits from player inventories and stashes.