All six of my voice cards now work. However, something strange is happening with the voice allocation. Whenever I play a note routed to Voice 1, it simultaneously activates voice 2. I can’t activate voice 2 by itself. Same with 3 and 4 in reverse - a voice routed to 4 also plays 3, but I can’t get a sound out of 3 separately. All 4 are SMR voice cards. Voices 5 and 6 work fine - they are SVF cards.
Of course, I’ve verified that all 6 voices are mapped to the same part / MIDI channel. I’m definitely puzzled here. Any ideas?