Hey everyone! Earlier today it was brought to our attention a bug that caused transactions to be sent via Admin and via the "Send Transaction" option in the Relayer page to fail with a generic gas estimation error. We have already tracked down the error and pushed a fix.
This issue affected only Ethereum Mainnet since the London hardfork, and didn't come up during our tests on the various testnets since it's related to the protocol's base fee, which is orders of magnitude bigger in mainnet than in testnets.
Apologies for the inconvenience, and please let us know if you stumble upon any other issues!