DaVinci Resolve 14 - Skipping Clips

DaVinci Resolve v14.3.0.014

I just downloaded this program a few days ago, and it seems to work well. Lag is almost non-existent, especially compared to Premiere Pro. But for some reason, there's this odd glitch/bug that happens only in a specific case.
I have two parts from a single clip that is over an hour long. It's fine when I put parts from other clips on top of or after it, but if I do that with a different part from the same long clip, it will start to skip frames and the audio will be out of sync. When the second part is done, it goes back to normal for the first part almost instantly. What's happening here?

DaVinci Resolve v14.3.0.014

I just downloaded this program a few days ago, and it seems to work well. Lag is almost non-existent, especially compared to Premiere Pro. But for some reason, there's this odd glitch/bug that happens only in a specific case.
I have two parts from a single clip that is over an hour long. It's fine when I put parts from other clips on top of or after it, but if I do that with a different part from the same long clip, it will start to skip frames and the audio will be out of sync. When the second part is done, it goes back to normal for the first part almost instantly. What's happening here?

Hi Yoshi

Can you supply bit more info? Is that clip a spanned AVCHD clip? Is it the same fps as Timeline frame rate?

Did you try to to create (and use) Optimized Media for it?

What camera was used to record the footage?