usb ports disappearing on 5,1 mac pro 2010

Help.

please, I have a Mac Pro 5,1 (2010), I just switched to from my 2008 3,1 Mac Pro as my recording/DAW computer, I've got everything finally sorted out as far as Logic Pro 10.3.3 and all my other plugins, licenses and such. Now I'm having an issue where the USB ports on my 2 Apple displays are not showing up, or one Display usb hub will show on system report but not the other or they don't "see" anything plugged into the ports. I only use these USB ports on the displays for 1 wired Apple mouse and an iLok key, they have always worked without issue with the 2008 Mac and have been working as well on the 2010 Mac while I've been getting the change over done. I've never seen this kind of problem before, the mouse and iLok key work fine themselves, just don't know why they would "disappear" along with the Display hub , the Display themselves are working as usual too. I'm running El Capitan 10.11.6 on both Macs which has always been very stable for use with Logic Pro 10.3.3. the 5,1 is a 12 core 2x 2.93Ghz X5670 with 48 Gb ram. I don't know if I need to reset SMC or NVRAM or both. I can't find anything in the system report showing a problem other than the Display usb going missing between shutdowns and startups, I really am at a loss, and need some help. I know I'm talking about what some consider ancient machines, but they're all I've got and can afford to write and record my music with and I need to get this working so I can finish my album and other projects I'm working on. With all that's going on the world, me being able to work as an recording artist and composer are what help me to stay sane and have purpose to my days.