Click Sound after Editing Small Bits

After I highlight a portion of the song and edit it (whether it be slow down the temp or change the volume) there is always a click/static sound at the start of the portion that was highlighted and at the end of it.

For instance, on a song that is 3:00 minutes long, I want to increase the volume from 2:31-2:39. So I highlight that part and edit it. After I do this, there is always a click/static noise at 2:31 and at 2:39. No matter what I do. Whether it’s increasing the volume, adding reverb, increasing or decreasing the tempo. I just want there to be a smooth sound with no interruptions after editing.

Has anyone ever experienced this?

Thanks

Clicks at edit points occur if the waveform on the two sides of the edit point do not match up - for example:

This can sometimes be avoided by adjusting the section to be edited to the nearest Zero Crossing Point

If there is still a click, then it can be repaired using the Repair effect: http://manual.audacityteam.org/o/man/repair.html

Thank you! This helps a lot.