Sound goes out of sync in the middle of the video?

I've been doing some gameplay videos, editing them with this, and lately i've noticed the sound goes out of sync by a second or two. It starts out ok though and perfectly synced.

I haven't done anything out-of-the-ordinary, just editen the way i always have done. Cutting a bit from the beginning and from the end, adding fadeouts. After rendering i start the file on windows player/bsplayer, sound is ok, skip about to halfway, the sound is off sync, skip to the end, the sound is even more of sync.

Any idea what could be causing this/what should i look for? I'm a total newbie in editing videos.

Gameplay videos may have changes in fps, which is a no-no in Resolve.

Convert them to another format and see if it stays in sync.

Ok, what's the most efficient way to convert them? I know only online converters atm for video and music.

Try Convert 3 for PC or EditReady for Mac.

Didn't seem to find Convert 3.. Can you give me a link?

There isn't a watermark in that software? I tried movavi (watermark), and wondershare's program, but that only converted 1/3 of the video.. And i really wouldn't like to pay the fee to use a program only for converting a video because of the sound sync issues, unless it's just a few euros. but above 20€ just for that..

Found one without watermark. Converted the video, but the sound syncing issues persisted.

Is it near to impossible to fix the issue somehow?

If you're using OBS Studio, there's a problem with the Media Foundation encoder it uses by default for some of the audio encoding. You can fix this by installing the Core Audio toolkit Apple supplies with iTunes, or by switching to a bitrate that doesn't use the MF encoder (192kbps should work).

It seems i found a solution! Software called Handbrake allowed me to convert the videos with constant fps setting.

Seems to be totally in sync still after i've exported and edited them with Davinci's resolve.

If anyone else comes across this issue, there is now a much better solution with OBS Studio. In Settings -> Output -> Recording, make sure you chose CBR (Constant Bitrate) from the drop-down next to Rate Control.