My audio file exported from a GarageBand project is having a volume reduction between 3 to 4 lufs. Why is this so?

Though I have auto normalise feature turned off, I am facing this problem since yesterday only. Tried restarting my Mac, but, this lowering of the exported audio continues. How can I have my GarageBand to behave normally as it was in the past? Is there any way out? Any deleting of preferences app such the Preference Manager we have in FCPX?

I hope to hear from you, and I need to state that I am worried because I need to master this song that is in preparation.

Regards