Only one train serves the station

[ShadeZP]

Hi to all. The idea of ​​my design was the constant simultaneous running of 2-3 trains for the consumers of the station. But in practice, only one train runs at a time. As soon as it was unloaded, a new one leaves the depot. It is similar to the behavior when there is a limit of 1 train for the station. But I didn't set any limits. What could be the problem ?