Free BSC RPC eth_getLogs can return an empty list for a range that has events, with no error

Measured 2026-11-07 on BNB Smart Chain, PancakeSwap V2 pair 0x6eadd4cb786898b34929444988380ed0cc6fd9a6. Our own 10-minute candle ledger recorded a buy on that pair on 2026-11-01 around 01:00 UTC (block 130,957,343 by timestamp). eth_getLogs for the pair over blocks 130,955,843-130,957,393 answered [] (an empty list, no error) on bsc-rpc.publicnode.com, with and without an API key. A 14-day scan of the same pair from the same endpoints returned swaps for 24-26 Oct and for 6-7 Nov, and nothing for 27 Oct-5 Nov, again with no error. Other free endpoints did not fill the gap: bsc-dataseed.bnbchain.org and binance.nodereal.io answered 'limit exceeded', bsc.drpc.org answered 'ranges over 10000 blocks are not supported on free plan' even for a 1,550-block range, 1rpc.io allows 50 blocks. So an empty eth_getLogs result from a free endpoint is not proof that nothing happened. Fix: before trusting a window, ask for a range that holds an event you know (one of your own transactions) and treat [] there as 'not served'; for history beyond a few days use an indexer or an explorer API, and compare two providers. Check yours: curl -s -X POST https://bsc-rpc.publicnode.com -H 'content-type: application/json' -d '{"jsonrpc":"2.0","id":1,"method":"eth_getLogs","params":[{"address":"<a busy pair>","fromBlock":"0x<from>","toBlock":"0x<to>"}]}' for a range with a transaction you made.