Audio sync problem!

Hi

I am new to this page, so i might be doing this wrong but lets have a go.

Okay. I am currently editing with 2 different cameras on FCPX. One at 50p and one at 59.94p AVCHD. My timeline is 24p. This is because I need slow smooth shots at certain parts.
I recorded my audio with the 59.94p camera.
I am trying to do basic multicam editing however, the sound will not match at all. I can match sound for about 3 to 4 words, then it goes back not matching. I can match anywhere in the clip for a 3 to 4 words, then it does the same.
Very odd and I cant get my head around it as I can match some audio, but not the whole clip.
Its just two different angles but sound from the one camera.

Any help for this please?

Thanks!!

What are the audio sampling rates of both clips? Are both 48kHz or are they different from each other? If they're different, this could cause audio drift over time.

Also, what is the audio sample rate of the Project timeline?

If you know you're going to do multicam, record all cameras with identical settings. I doubt .06 of a frame would throw audio off that bad that soon. But, it could happen. What camera make/models did you use?

All cameras are 48 and the timeline itself.
Yeah, for some reason I couldn't get both cameras at 50p.
The cameras are a Sony and a dslr.