Export volume problem

Hi, I’ve searched and read posts all the way back to 2009, no definite answers. Rechecked all the settings I’m familiar with and hoping someone has a “here’s your problem” fix. I’ve been doing this for 20 years so I know a little about DAW. I can get a great mix, nice levels on the master outs, sounds killer on the monitors. I can 0db on the master out but when I export, same format, the mix barely reaches -9db. And I’ve checked this through protools at work.

No problem before but this was my first try with group channels, thought maybe I was missing something small in the process Again, rechecked all channel routing, insert settings and device settings and I see nothing obvious. Except that hundreds of people all the way back to 2009 have reported this very same issue. Wondering if anyone has figured this out. Again, great success up to this point with the software but this problem has got me stumped.

Thanks, Gene