I do not know of a Zorro problem with IB historical data. Nor that Zorro requests "5 hours" or "trades". Only prices and volume are requested, and only at session start. If you cannot download some specific IB data, please contact Support.

IB has strongly limited their historical data until 2016. That was mentioned in the manual, maybe that has confused you. The current limits are listed on the IB website. It's normally 1 year. Zorro, and any other software, can download all historical data within those limits.