I noticed that when you have multiple vehicle depots and using the new mass upgrade tool sometimes the vehicle won't retain its settings. It seems to happen when the vehicle that is being upgraded enters a depot other than the one where the upgraded vehicle is being constructed. Shown in the screenshots, we have in the left depot a dump truck ready for upgrade and the truck moving to the right depot is the one being upgraded. in the second screenshot you can see the new large dump truck is no longer connected to the mining tower.
Link to save right before truck is being upgraded: https://drive.google.com/file/d/1j0gboi7K0R3xvJjqkLrfOqqo8SPH4pHY/view?usp=sharing
in the linked save, the old truck is going in to the left depot and the new truck is coming out of the right depot.
