The Polygon Foundation restored its consensus and finality functions on its L2 Ethereum network

The Polygon Foundation reported that its consensus and finality were back online on its layer-2 Ethereum network after a bug disrupted node synchronization. It said it implemented a hard fork to resolve the software bug that interfered with RPC nodes, restoring smooth communication between apps and the blockchain.

On X, the company shared:

The hard fork has been successfully completed, and milestones are now processing normally along with state sync. Checkpoints are going through, and consensus finalization has been fully restored on Polygon PoS.

Polygon network’s finality had a 10-15 minute delay, though they maintained block production

As reported by Cryptopolitan early on Wednesday, a bug in Bor and Erigon nodes led to a short disruption in consensus finality on Polygon’s network. The software issue interfered with Remote Procedure Call (RPC) services, which meant applications using Polygon had trouble connecting to the network.

Nonetheless, even with the disruption, Polygon remained online. It continued block production, though finality was delayed by around 10–15 minutes, with several RPC providers and validators having to revert to the last finalized block to get back in sync. Later, the company stated that rebooting the affected nodes successfully restored functionality for some users.

Polygon co-founder Sandeep Nailwal explained that the disruption was triggered by a faulty proposal from a validator, which pushed several Bor nodes onto separate forks and halted block production. He noted that fixes were rolled out through Heimdall v0.3.1, introducing a hard fork to remove the faulty milestone, and Bor 2.2.11 beta2 purged it from the database. With these updates, nodes are now fully operational, and the network’s checkpoint and milestone finality process has returned to normal.

Moreover, the network on their official X account stated that they will keep a close eye on the network to ensure everything keeps running smoothly.

Polygon’s Heimdall V2 mainnet activity was disrupted in July

A few months back, Polygon encountered a comparable incident, during which the Heimdall V2 mainnet, the consensus client responsible for coordinating node communication in Polygon’s PoS system, was offline for roughly one hour.

The network’s disruption was linked to a  “consensus bug.” Though the software glitch did not affect the Bor layer block production. Soon after Heimdall returned online, minor synchronization inconsistencies appeared across several RPC providers’ Bor nodes, which the network promptly addressed. 

Before the incident, Polygon had just launched the Heimdall V2 upgrade a few weeks back. The upgrade cut finality times to about five seconds while moving the network to a new stack powered by CometBFT and Cosmos-SDK v0.50. Naiwal had even described it as “the most technically complex hard fork Polygon proof-of-stake (PoS) has seen since its launch in 2020.” 

Although blockchain projects aim for faster block times and higher throughput, these upgrades also add complexity and potential points of failure. Heimdall V1 has also faced network issues before. Back in March 2022, a bug in Heimdall knocked Polygon offline for a few hours because validators weren’t all on the same version of the chain.

Want your project in front of crypto’s top minds? Feature it in our next industry report, where data meets impact.