There are issues with your new USBPorts.kext.
You have set all the USB2 ports served from the physical/Header USB 3 ports with connector type (0), i.e. as USB2. This is wrong. The virtual USB2 ports served from a USB3 physical or Header port should always be set to match the main physical/header connector type, i.e. USB3 (3).
You don't say if your Dell OptiPlex 5080 is the MT or SFF model, so I am going to assume it is the SFF model in my explanation below.
The OptiPlex 5080 SFF has the following USB ports:
Front
- 2 x USB2 (2 x (0) - 2 x USB2 physical)
- 1 x USB3 (2 x (3) - 1 x UB3 physical & 1 x USB2 virtual ports)
- 1 x Type-C (2 x Type-c +switch (9) - 1 x Type-C physical & 1 x Type-c USB2 virtual ports)
Rear
- 2 x USB2 (2 x (0) - 2 x USB2 physical)
- 4 x USB3 (8 x (3) - 4 x UB3 physical & 4 x USB2 virtual ports)
Internally
- 1 x 9-pin USB2 header (2 x (255) - 2 x Internal USB2 ports)
This means you system has a maximum of 18 USB ports.
- You probably only require and can use 1 of the 2 Internal ports, as the Bluetooth connection will take up the space of the whole 9-pin header.
- You may not want or need to activate the Type-c USB2 virtual port.
- That leaves a maximum of 16 ports available with a 15 port limit. So one of the other 16 ports would need to be left unused, to make the most of the 15 port limit imposed by Apple.
Your new USBPorts.kext contains and activates the following:
- 9 x USB2 physical ports, with connector type (0):
- HS01, HS05, HS06, HS07, HS08, HS09, HS10, HS12 & HS13.
- 4 x USB3 physical ports, with connector type (3):
- 1 x Type-C port, with connector type (9):
- 1 x Internal header port, with connector type (255):
The 1st section detailing the USB2 ports above is wrong, as your system only contains 4 x USB2 physical ports. 5 of these 9 x ports should be set with connector type (3), as they are served from a physical USB3 port.
From experience, I would look at ports HS01, HS05, HS06 and HS07 as being set with the wrong connector type. As the UB3 ports usually have matched pairs of ports, i.e. SS01/HS01, SS05/HS05 etc. That is how the USB ports on my OptiPlex 3050 SFF are configured.
Also I would think that HS02 is likely the 'companion' port for the Type-C physical port.
I am not sure that HS14 is the Bluetooth port. I have a feeling that HS03 & HS04 serve the Internal USB2 Header port. Again as that is how my OptiPlex 3050 is configured.
Well I am sure that has given you something to think about. Plus you need to double/triple check the USB ports are identified correctly and are set with the correct connector type, before creating a new USBPorts.kext.