Unpredictable pauses and buzzzing

I was able to import a music bed track but when playing it back, or trying to add another instrument track, it will pause or buzz for no reason, which ruins the recording. this lasts only a second or two but obviously there is a problem here as that shouldn’t happen. I increased the buffer thinking it as a latency issue, but that didn’t help. I am new to Cubase Elements so any help would be much appreciated.