The Graph protocol is midway through its migration to L2 on Arbitrum. That means that graph indexers on ETH mainnet are moving over to the Arbitrum chain and any staked GRT tokens on mainnet also need to be manually migrated to Arbitrum.
Staked is planning to move its remaining stake to Arbitrum in the first half of November, so we ask that you move your delegations over as well so that you can continue earning rewards. Instructions can be found here: https://thegraph.com/docs/en/arbitrum/arbitrum-faq/