Other people had this issue too.
As long as you are sure that the files have the same sample rate than the project, then the culprit is the audio device. Open the driver and check if the sample rate is the same as the project. For some reason some drivers fail to change their sample rate automatically when they get loaded in an ASIO application.
But i never had his happen in another DAW. Instead of playing at the wrong pitch / tempo, Cubase should throw up an error message, like happens in Samplitude when there’s a SR / soundcard mis-match.