I find there's a lot of set up and troubleshooting whenever I'm putting the BSP in the chain, but it's always something fixable.
I wouldn't work with, say, the virus as both midi in and out. I'd have a non-sequenced keyboard going in. To test and isolate the problem. I'd also check that keyboard as to what it sends, when.
For instance, I was sending midi clock to BSP from machinedrum. But when I played the machine drums own sequence, it was sending midi notes to the BSP and transposing its sequences.
So I had to turn midi send off in the machine drum. So it could place sequences without messing with everyone else.
mCC has a section I believe which tells the BSP which channels to listen for in midi in.
Hope you find a solution.