CC, I looked at the final mix in Orban, and did the stereo mix in Reaper with SWS Loudness. The LUFS readings were almost identical. Then I split the stereo track into two monos to compare the channels. That's what is in the screen cap above. All faders are set at 0, so I didn't boost or drop anything.
Maybe I'm hearing something different, but it seems the whole song has a distorted "haze", including the drums and the vocals in the chorus. I listened on two different systems, and it was apparent to me on both. That just makes a good song unlistenable for me.
It may be that the original instruments have that distortion on them. That's possible with synths depending on the waveform built. But the vocals should NOT have that type of sound unless that's what the singer wants and purposely made them that way.
The OP asked it it was mastered too loud. Certainly it will get squashed by any of the streaming services, but it may not just be an issue with mastering. If the original tracks were recorded loud and have distortion, then that's going to carry through the whole process. By that point, the damage is done, so no amount of volume decrease will change the overall sound.
Perhaps someone else has some ideas.