We've seen a number of issues with Polygon nodes over the last 24 hours including:
- eth_getBalance returning an error "header for hash not found"
- eth_estimateGas returning low gas estimations that can cause transactions to revert (out of gas)
The gasLimit parameter is required when sending transactions to the Defender Relayer API. If DefenderRelaySigner is being used to send the transaction and a gasLimit is not explicitly defined, the etherjs populateTransaction logic is used within the client to estimate the gas limit.
Unfortunately this is problematic if a provider is returning the wrong values for that eth_estimateGas call. But beyond that call, we don't really have any ability to estimate gas for a transaction. The way to override it is for the user to provide a gasLimit value, which will bypass the eth_estimateGas call.