Duplicate id in couchbase

I caught a bug on our couchbase 3.1.6 - the duplicate id.

When you open each of them, the same content is displayed (doc1). But the ‘view indexer’ handles other content (doc2). I delete the document doc1 - doc2 in place. But when I try to open the remaining document, I get an error “Error: notfound (Document does not exists)”.
I re-create the document - the situation is repeated.
Most likely the situation was due to a single server crash and recovery on xdcr.
How can I fix it?