If you have two Midisports plugged in they have 2 ins and 2 outs. So when I am referring to Output 3 I am referring to Output 1 of the second device. The problem is that the newest M-Audio driver is supposed to be Windows 10 ready but was released 7 years ago and there is an issue with the pre-requisite it fails to install. I think it was written with 32bit OS’s in mind when M-Audio was owned by AVID and nobody has updated it
Fortunately It runs off Class compliment drivers so you do get some functionality. I think you need the driver to run 2 devices on the same machine. There is no issue with the windows driver if just running one device. You are meant to be able to run two though.