I just tried View > DBA > Storage > Redo Log Groups on a SYS connection to a local 18.104.22.168 DB. No duplicates. So I tried...
1. Adding another group (#4, three already exist). No duplicates.
2. Adding another member to group #4. No duplicates.
3. Expanding all from the Redo Log Groups node, then refreshing. No duplicates.
Please show us exactly what you mean by "groups are duplicated" even though it seems obvious. Do you see duplicates in the DBA tree and also in the Redo Log Groups tab? Also, provide specific details on your OS, JDK, and so on.
SQL Developer Team
but I think is a RAC bug. I have two instance with 6 redo log group (3 group on the first node and three group on the second node with totally 6 redo log files). SQL developer show 6 group but duplicated (2xone group, 2xsecond group...) and 12 redo log files and it's not correct.