TikTok Audio so much louder than my voiceover

Hello, I’m a new creator, and I’ve run into a frustrating issue I can’t figure out. When I add a TikTok sound (like a song) to my video, it’s way louder than the audio I already have.

Here’s my process:
I record a video of myself talking in CapCut and use the voice isolation feature. Then I download the video and upload it to TikTok. From there, I add captions and choose a background sound from TikTok’s audio library.

But no matter what I pick, the background audio completely overpowers my voice. I end up having to turn the TikTok audio volume down to almost zero.

Is there something I’m missing? Any tips or settings I should try? Thanks in advance!