most probably, the new channels you create, they do actually exist!
sometimes, esp. when reducing the number of ports of a bus for example, they may not show properly with their correct names on the connections/graph GUIs (qtractor, qjackctl and even qpwgraph), due to their own inventory recycle process--nothing related to aux-send routing matrix per se (because, as said, this is all done internally to qtractor...)
as told before, a simple full "Refresh" may show them back again, as they are indeed out there for x sake.
most probably, the new channels you create, they do actually exist!
sometimes, esp. when reducing the number of ports of a bus for example, they may not show properly with their correct names on the connections/graph GUIs (qtractor, qjackctl and even qpwgraph), due to their own inventory recycle process--nothing related to aux-send routing matrix per se (because, as said, this is all done internally to qtractor...)
as told before, a simple full "Refresh" may show them back again, as they are indeed out there for x sake.
but yes, @bluebell will tell the verdict ;)