This glitch seems to be a mix of server and client lag. But mostly server lag is likely more responsible.
The railroad glitches seem to be occurring on the client side of people (Usually). You can tell that it is client sided since only one person seems to see a particular thing in the rails most the time. Because of this I can probably only come to the idea that this is because the server is either lagging to the point where it causes duplicate information. Or that classic 's server is lagging to the point where when the client tries to load up information from the server so it knows what goes where, It lags and puts a random object there based on your previous locations it seems.
If either of these are the case, I mean personally classic should have seen this kind of issue coming