I’m pretty sure there’s nothing wrong. As far as I remember, the start failures were caused by communication problems between control units, possibly related to communication order.
From my software dev perspective, the startup delay could simply be extra time to ensure everything is ready before the car starts.
In my case, the delay has increased compared to delivery over the span of a few updates and I haven’t had any start failures since then. Maybe coincidence, maybe not, but a few seconds don’t matter as long as it starts reliably.