HD Native/ HD IO gain/distortion issue. Help!

[tronnyjenkins]

I will try to keep this short but include all pertinent data.

Mac Pro Late 2009 12 Core 3.46
Tried using both Snow Leopard with PT10 and
High Sierra with PT Ultimate.
DSubs are going into +4.

We recently built a new desk and so therefore I had to change our patch bays around. We also upgraded our Pro Tools setup to Ultimate from 10HD. Before this, there were no issues.

What's happening:
inputs 1-8 seem to be clean and of a normal gain level.
inputs 9-16 are low gain and have distortion but all match.

Are there any software issues to check? Are there any known HD IO issues that might cause this? I of course am concerned that it is in a bank of 8 since those are the number of ins or outs on the interface itself.

Got a big drum session on Friday so panic mode starts now...

Help!