I'm not heavily modded, just some good mods to enhance the experience! I don't think I have a mod that does what you just described.
Mod list: base, elevated-rails, quality, space-age, AsphaltRoadsPatched, Automatic_Train_Painter, Better-Power-Armor-Grid, bobinserters, BottleneckLite, car-finder, CleanFloor, Dectorio, even-distribution, flib, helmod, Hovercrafts, InlaidLampsExtended, Inventory Sensor, ixuClock, kry_stdlib, laser_tanks, manual-inventory-sort, nixie-tubes, PavementDriveAssistContinued, RailLogisticsDispatcher, reverse-factory, Robot256Lib, textplates, underground-pipe-pack, valves, vehicle-wagon-graphics, VehicleSnap, VehicleWagon2, visual_tracers
I’m using the same list of mods when playing on your demo save, and the problem doesn’t occur.
But I tested something else with a friend: I hosted a game on my PC instead of playing on a server, and the bug doesn’t happen when I’m the host. He was the client, so he experienced the bug.
It seems to be an issue for clients only.