$curl -s https://online-go.com/api/v1/players/449941/full | jq .trophies.tournament_id
In my case only one tournament is affected.
I had a quick look at the other winners of tournament 39400 and 38467.
It seems, all the “Blitz 19x19 Elimination Tournament” are double badged. Player 535250 has also a 9x9 Blitz Single elimination doubled.
I think this is a bug in the code for resolving the Single Elimination Tournaments, since in the short list I’ve looked at, all affected were and the others weren’t “single elimination” tournaments.