When you have an intraday timeframe already added in an EOD profile, then you remove it or add another intraday timeframe, it seems to cause a problem resulting in an IQ Feed reconnect as well as a possible error. I'll report that. You may not have seen the issue had you added the 60m & 240m timeframe first.
Also that spread feature was never coded to work with intraday timeframes. The feature was made many years ago long before the intraday timeframe capability was added to EOD profiles. I'll report it as a bug, but I would recommend not using spreads with intraday timeframes for now or do so at your own risk.