Existing installation, has been working properly for weeks. Mios Studio 2.4.2 stopped seeing the LPC after a query. Tried 2.4.4, same result  PC says no midi devices connected, although the USB cable is in place. Reconnected 2x2 USB interface to pic8 and PC, and query successful so PC USB working ok., and didn't run the loopback test.  The surface unit connected to the LPC boots up as normal (with USB cable connected), all functions seem normal.  Access to DINs, DOUTS, Router, mon. all are nor