Yes, you need to click on the "view more" option:
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Lumo-only walkup fares are then shown, although it's far from clear that these tickets are restricted to Lumo services:
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And the term "ECTL ONLY" is not going to mean anything to 99% of passengers:
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Trainline are now selling the LumoFixed tickets; however their white label site (used by XC, Northern, Scotrail etc.) is still only showing the walkup fares. TrainSplit are only showing Lumo's walkup fares and MixingDeck based sites (used by GWR, SWR & TPE) aren't showing Lumo's flexible or Advance fares at all.
The fares have been uploaded. BR Fares only shows fares that are available for travel today. LumoFixed tickets are shown on BR Fares because they are, theoretically, available for travel today - there are just no publicly advertised services, hence you can't buy them. Whereas the flexible fares are only available for purchase from 25 October, so will only appear on BR Fares on that date.
Lumo have had to fit within the existing ECML timetable, which wasn't designed to accommodate an additional fast service. When the ECML recast eventually happens, Lumo should get some better paths, although they will inevitably still have some pathing ("slack"). There are also a number of limitations on the calls they are allowed to make due to their access rights.