finalized_l2 always zero?

[TurtleSnail]

I am running Optimism mainnet with Erigon node.

curl http://127.0.0.1:9995 -s -X POST -H "Content-Type: application/json"  -d '{"jsonrpc": "2.0","method": "optimism_syncStatus","params": [],"id": 1}' | jq -r '.result | "\(.finalized_l1.number) \(.current_l1.number) \(.finalized_l2.number) \(.unsafe_l2.number)"'
21772487 0 0 131533262

(nb:9995 is node rpc port.)

As you can see;
finalized_l1 looks good.
unsafe_l2 also looks good.

But current_l1 and finalized_l2 are always zero.

I am also running another full node (not archive node) using geth, when i perform the same query, all fields are reported.

Is it a bug? or something else?