The latest developments in the testing phases of the upcoming Ethereum upgrade were detailed in a ‘London Testnet Retrospective’ posted by lead developer Tim Beiko on July 21.
It reported that the OpenEthereum client noticed their node had stopped progressing on the Ropsten testnet on July 21. The issue, it turns out, was not with the client but with go-ethereum protocol and Geth client which checked the balance of the transaction sender for 1559-style transactions.
Some clients rejected the block while others accepted it and continued processing:
“Specifically, OpenEthereum and Besu rejected the transaction/block, while Nethermind, go-ethereum, and Erigon accepted them.”