From my experience, it's an IB issue. Have had similar problems with Ninja and Multicharts using IB feed both today and Thurs of last week. Otherwise, IB has been trouble-free. Some wild times we're experiencing these last few weeks, so expect and be prepared for data issues.
Using MC, my quick-fix solution is to completely delete the contract from the quote manager and start new ES template with only 1-2 days worth of backfill. When EOD rolls around with less traffic, I reload necessary historical.
Also try to have your systems loaded and running 30-60mins before NY open (930EST).