After LoTW had an outage this past weekend, it seems to have double processed some uploads which caused duplicate QSOs to be entered. There’s a discussion on the LoTW Yahoo Group
I seem to have this same issue with duplicated QSOs. I saw right after my upload was processed on Tuesday that LoTW processed the same log twice, and though my initial review showed that it detected the records as duplicates and ignored them, but that’s not the case. I’ll include screen snippets here for those that might want to check their own data and hopefully the screen snippets come out ok in emails. If not, the message might read better on the web in the Yahoo group pages.This overall issue would seem to be more appropriately resolved by the ARRL vs individuals contacting the ARRL as they should be able to query LoTW and find/remove any true duplicate which is where the uploaded data matches and the only difference is the LoTW generated id (and whatever else they might track and not expose on the front end).
On your Account Activity page at https://lotw.arrl.org/lotwuser/account?accountcmd=activity you would see a duplicate indicating your one upload was processed twice. Mine looks like the first 2 lines here:
The 2nd processing seemed to indicate that it ignored the duplicates as seen here: