I'm not sure if this is a bug or not but the trains are not charging, they have a flashing fuel indicator.

I have them at a Charging Station and the station is powered, am I missing something here or is this broken?

I think it's broken, having the same issue

After testing it, it seems to work fine.
Make sure trains are in Automatic mode, they will not charge in manual, and thats something i cant fix due to how the trains check what charging station to draw power from.

I have a similar issue. I am building a relatively big train network and the trains sometimes stop charging. It seems to follow a pattern, so it's not totally random, but I didn't figure it out.
Can you help or can I send you the savegame and you can debug this?
Thanks in advance for any help :)

PS: I made a little unlisted video to demonstrate: https://youtu.be/xY7_WPLHLSs