Audio distortion with multiple audio tracks

Hi all,
When I try to put more than 1 audio clip the audio comes back clipping and distorted. I've got a scene where I've got dialogue in Track 1, then I put dialogue from another take in Track 2 to play at the same time, but it doesn't play normally. It's all messed up.
Is there a solution?

[Gary Adams]

Hello Russel. You will get more help if you provide what hardware and software you are using in this case.

Regards, Gary

Hello Russel. You will get more help if you provide what hardware and software you are using in this case.

Regards, Gary

Hey Gary. I'm on Davinci Resolve 12.5, Windows 10. I don't use any other plugins or programs. I do all my editing through the program. I film on my Galaxy 7, and upload as .mp4.
Any other information I should provide?

When I add in sound effects, or music, or other tracks not related to the other footage it runs smoothly. For some reason it's only when I use audio from my camera recorded footage.
Any advice?