When future contract orders get routed?

Please explain when orders for MNQ and NQ future contracts get placed in my connected IB account when autotrading?

I entered BTO orders for both during maintenance window (markets closed hour), and it did not get placed with my broker before market openned, and not even 5 minutes after the markets opened. I ended up replacing the ‘working’ order, and once I did, it went straight to the IB account.

Can we not rely that orders will be placed with broker before markets open? Please explain.