Could you also run this tctl command, does it throw the same error?
./tctl workflow observe -wid d6109fc7e6be49d2ab78ecc3122abc51__9d16dec1-b71e-4a8e-81f8-338f805efbff -rid 156782b1-faea-434d-beaf-c7daace1077b
Would you expect some specific data in the workflow history to possibly exceed it? For example quite big payloads (inputs, results?)
i will speak to my team to see if we should increase the max grpc message size or possibly look deeper into why this happened with your workflow