kad: get_providers() sometimes resolves with FinishedWithNoAdditionalRecord and no closest peers

I have an app that does a lot of get_providers() calls via Kademlia.

Most of the time they finish successfully, but occasionally the first and only query result is GetProvidersOk::FinishedWithNoAdditionalRecord with empty list of closest peers, which seems wrong both because the key is actually present on the network and due to closest peers list being empty.

It would be reasonable if the key was not found and I got a list of closest peers, but the fact that list of closest peers is empty while Kademlia k-buckets are not empty tells me something is off here, but I'm having a hard time tracing what, where and why.

Sometimes I first get GetProvidersOk::FoundProviders with empty list followed by GetProvidersOk::FinishedWithNoAdditionalRecord with a single peer ID, again for a key that definitely exists on the network.

Any suggestions for debugging steps here?

libp2p-kad 0.45.3 (latest at the moment of writing), disjoint_query_paths: true

Start by reproducing the reported behavior with libp2p-kad 0.45.3, focusing on get_providers() and disjoint_query_paths: true. Trace how the query produces FoundProviders and FinishedWithNoAdditionalRecord results, especially the closest-peers list. Done means identifying the cause of the empty results and establishing the expected behavior or a focused fix with regression coverage.