Help. Midi Sends Not Functioning

Hi folks, I'm hoping to find some assistance here.
I am using a Keith McMillen Softstep 2 into Belkin powered usb hub into an iConnectivity Audio 4+ with an iPad Air running Loopy HD. There is also an Akai MPK Mini in the mix, same routing as Softstep. I have had all my midi bindings set for a while and they have been functional. Suddenly none of them work. I did not change anything. Weirder still, if I click "Add Binding" Loopy HD recognizes my midi controllers (both Softstep and MPK Mini) and I am able to recreate my bindings from scratch. When I try to then use the controllers to control loopy, they do not work, as if Loopy is not receiving the midi sends. Has anyone experiences such a problem? Any advice would be helpful. I am trying to set up a live looping rig and stuff like this is a deal breaker.
Thanks so much!
Sasha K