Disclaimer: I've read comments before write my own.

It remembers me long history of failures of post-soviet passenger railroad booking system.

They constantly have issues, it is just impossible reliable buy tickets when hot season.

Situation becomes much better latest years (to be honest, we just don't see them), just because free market - railroads give up large share of load to other transport - to air, buses, private autos, and also large part of tourists go abroad.