After 2 failed prints, 1st with the sacrificial wall coming out as "jail-bar-> lll" instead of the wall (aborted print) and 2nd as a complete printed "hair-less" lion (sacrificial wall only printed till 0.8mm height), l had decided that it's isn't the printer's fault.
Using Cura 2.3.1 as slicer, l keep my usual setting (without support) and play around with the scaling. That's when l realised that when loading the Big lion .stl, it was auto scaled down to 49% as my bed is only 200x200x200. At that scale, the wall although visible in SOLID preview, disappearing in LAYER preview. SO any further down scaling will only produce a hair-less print.
Using the regular lion .stl (1st file in the Thing Files), it loads with the wall at 100% (all this is now viewed in LAYER preview mode). At 50% down scale, the wall disappear. At 70%, the wall appears like the 1st failed print "jail-bar -> lll". Increasing to 75%, the wall finally appears as it suppose to. A 3rd successful print shows that above observation is true.
It might not apply to all versions of Cura but my suggestion will be to preview both in SOLID & LAYER mode and you will know what will be printed and what won't.