Why are sounds quieter when imported?

All the sounds are approximately 3db quieter when I import them into Unreal. Why?
For example, I’ve created a short music piece in my DAW, mixed it to a true peak of -0.1db and an integrated LUFS of -10.6, but as soon as I import it into Unreal and preview it in the content browser it has a true peak of -2.9db and -13.6 int LUFS.

This doesn’t just go for loud sounds such as this, all the sounds I import are approximately 3db quieter. Please help.