In the last TxC release (27/02), the 312 extension from South Croydon to Cannons Hill is only present for Southbound trips, but the Northbound direction only runs from Grovelands Rd to Norwood Junction (so only part of the extension is visible for Northbound trips): the data is missing the Northbound segment from Cannons Hill to Grovelands Rd.
The data does:
Norwood → Cannons Hill
Grovelands Rd → Norwood
But Norwood → Grovelands Rd is nowhere to be seen…
Technically, all the northbound stops are there but the first six links (covering Canons Hill to Grovelands Road) all show running time of zero. Then 1 minute to Tesco, another minute to Purley Station and then umpteen minutes to get to the next stop (Downlands Precinct). My impression is that the true running times for the section up to Grovelands Road have been shoved into this last link. In which case what comes out of JP will be right at Canons Hill and from Downlands Precinct onwards but wrong for all stops after Canons Hill up to and including Purley Station (i e not just up to Grovelands Road). I have a feeling that Downlands Precinct will turn out to be the first intermediate timing point used in the working timetable, so it is, like for some other routes in the past, a faulty allocation of running time between the Canons Hill and Downlands Precinct timing points. Very similar to the sort of thing I intend to report on the Journey Planner Datastore thread that I started a few days ago.