“Consumer Reports factors build quality issues that require repair into our reliability calculations, but they are not weighted as heavily as more serious problems, such as those with the engine, transmission, or drivetrain.”

I’ll take a guess that this is the source of the weird counterintuitive results. EVs have a bunch of minor QC issues resulting from their comparatively newer and less tested assembly lines, while ICE vehicles have fewer but much more severe issues. Thus they’re rated as more reliable by CR even though the average cost of maintenance is far higher.