For years in the 2000s/2010s there was a short (less than 10 mins) connection at Doncaster for Sheffield off the 1900 from Edinburgh on Saturday evenings which allowed passengers to easily catch the last tram/bus home. The reliability of the Edinburgh train began to deteriorate and the connection was frequently missed. After a couple of years of this the 'connection' was retimed to leave <7 mins after the scheduled arrival from Edinburgh (I can't remember whether the retiming was to the arriving or departing train or both) meaning it was no longer an official connection. No explanation was forthcoming but, in the absence of one, it did seem rather like a deliberate decision to avoid paying for Delay Repay or taxis.
The reliability of the train from Edinburgh was obviously deemed bad enough to be retimed and the root cause of the reliability could have been a great number of things. Timetable changes have a number of impacts as a result, and passenger groups for the same TOC will actively advocate for the completely opposite from each other because of the resulting connectional issues!