I had the same problem yesterday on GNTC when using IB´s datafeed with motivewave community editon. The 1m chart wasn`t backfilled for some minutes. If i were in a trade this would have been a nightmare. I came to the conclusion not to trade with IB´s datafeed when using a third party software. Either i use tradingview for charting and IB´s booktrader for order entry or i use sierrachart with their datafeed for charting and trading.