Does anyone have any idea why when we create and process a new order it would be creating a duplicate order with the exact same order number?
This sounds similar to an issue we observed. Tessitura gave this advice:
There is a known issue in V12 where the default Production Season (id 0 in T_PROD_SEASON) and the default Performance (ID 0 in T_PERF) get their season set to something other than 0. It should always be 0 for these two rows. If it gets set to something else it can cause display issues in the client.
If you can fix that yourself you should check it, otherwise open a TASK ticket. What happens is that saving certain changes in production elements will sometimes send you to the default performance or production season (the real source of the bug) and then you might accidentally make edits to those.