Trains get stuck searching for path

Issue description

My trains keep stopping in random locations saying "Waiting for free track" even if there is a free track. It appears random, with trains stopping in the middle of straight sections.
Video:

Reproduction steps

1. Load the save
2. Run the game and keep an eye on the train network
3. Eventually a train will just stop and back up the whole system

Game version and build number

v0.7.9a (b500)

Operating system

Windows

Attachments

26-01-02_16-09-autosave.save

Save when this happened and replace the file. I waited a year without a result.

Broken train - stopped all coal delivery.save

https://discord.com/channels/803508556325584926/1465056321014595799

Link to Discord issues, with accounts of the same/similar issue.