The problem is with Cura. Not the printer. NEVER PRINT anything without looking at it in slice view first. You would have seen these holes in slice view.
There are several possibilities. It could be that the walls that aren't printing are too think. In general if nozzle is .4mm then wall must be at least .8mm (1mm to be safe).
Or you may have extra hidden walls inside your walls. You can test this easily by going into xray mode in cura (that's one of the 5 or so view modes for your model in cura). If you see *any* red then that's a problem with your cad model. Typically sketchup creates lots of errors (lots of red).
Can you give us more informations about your print and your printer ?
What resolution, infill, nozzle diameter, speed, how much time did your machine print ?
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