No not correct. The basic design is for automatic charging of the house batteries when driving. There can be a delay before the charging starts from the electronics if any or immediate when enabled from the ignition.
Why would it be designed otherwise? If it's manual as you're describing then first confirm from the mfg that it's working as designed and then change it, IMHO.
The emergency start (or whatever it's called for your rig) is designed to start the engine when the chassis battery doesn't by itself for whatever reason.