I draw the same part with different walls thikness : 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, 0.41, 0.42
CURA is configured to use a 0.4 nozzle with a "line width" of 0.35
The object can be print when the line width of the model is >= 0.40
Note : "print thin walls" not used.
When "print thin walls" is used, the object can be printed but not without some problems if you look closely