Audio exporting louder than sequence

I am exporting a feature-length sequence in 3 parts. The output keeps exporting ~6db louder than the timeline. This is noticeable during playback as well as in the levels when bringing the clips back into Premiere to stitch them together. When I adjust the clip volume to -7 it sounds fine.

Any insight into why this is happening? I do not have the Loudness Normalization effect turned on and cannot find any other out-of the ordinary settings. Here is more info:

Sequence is 48 kHz. I had a track volume setting of -1.3 on the original timeline. I tried exporting w/ & w/o; same problem. Problem is happening regardless of whether I use headphones or desktop audio (output is clipping when I bring it into Premiere timeline. Have checked out the Number of channels (2) and audio hardware, not finding any problems or adjustments that would have caused this.

Thanks in advance!