If it is just to a neighboring country, it usually works well. Or if it is a direct connection through several countries. But if you have to change in a country

If it is just to a neighboring country, it usually works well. Or if it is a direct connection through several countries. But if you have to change in a country you are just passing through, it all breaks down. Best to install the apps of all train operators you are going to use. Trainline et al would be great if they didn't mark connections as sold out so often that are perfectly available through the train operator's app.