Beeping sound between clips.

[Bardo]

Hello, I have recently bought the software and I'm a little acquainted with DAWs. I noticed you have a practical way to copy paste by directly extending a clip. It works great with my MIDI tracks, but with recorded audio it has a limit (Usually can just double it's original lenght).
Second, and most important really, Sometimes when I copy the paste an audio clip, I get a small bleeping sound at the beginning or end of it. I cut them with the clip splitting options, so it's no human mistake at least there.
Anyways, I'm working on a long bass line full of repetitions, and would be very glad if you helped me on this, as actually playing the entire track would be a little dull and uneasy.
If you could just at least point me towards the right part of the documentation, that'd be great.