It is the Globex contracts that won't backfill properly. ES, NQ, EMD, GE and 6E all have problems. YM, ZN and TF backfill fine and cash indices backfill fine. IB please fix your backfill server for Globex contracts.
Experiencing the same problem. ECBOT backfill (YM/ZB) better. Globex backfill (NQ/ES) is a hit or miss even after market closes. The time interval of 10sec in the historical data queries adds to the frustration.
Hadn't had a problem the last couple of days. Today I can't get any backfill. Anybody else or is it just my connection?