Any advice on how to avoid copyright claims that is caused by the game's soundtrack? Obviously I don't want to mute/replace the audio for certain parts of the run for verification purposes.

yeah all you can really do is hope that the publisher or whatever is fine with having gameplay with music uploaded

@jackzfiml I don't monetize my speedruns, but some of them got copyright-claimed for small piece in the game's soundtrack. The videos even got ads on them.

@jackzfiml given the opportunity, why not monetize your runs?

Either way the bigger problem with certain music copyright claims is some of them will make your video unreviewable in most regions which is super fucked for submitting the game.

I've just realised I'm getting this issue. Can my run still be verified if I mute the audio segment casing the copyright issue? What if I mute that segment after the run has already been verified?

It depends whether the leaderboard requires game audio. Check the game rules, and ask the mod if you’re not sure.

I would recommend informing a mod before editing a video for a verified run.

I have to agree with @Pear, When it comes to uploading your videos, you should check the games’ rules to apply them to your videos before editing it. So you need to be careful because once the moderators know that your video has a segment of copyright your video will be rejected.