I think I found an issue in BH-web. Play along and see if you agree. I am trying to change the Port of a MIDI Device from a given Port back to 'All'. Refer to the figures.
1) Before attempt, we see two devices - HD500 on Port 'iConnectAudio4+ DIN', channel 16, and VL3 on All, ch 15.
2) We've clicked Edit for HD500. Pull dropdown for Port, deselect 'iConnectAudio4+ DIN', select 'All'.
3) Hit 'Save' and get error - 'The channel selected is already in use by another device . Your changes have not been saved'. Hmm. I thought VL3 was on 15...
4) It is! What is this conflict of which you speak? Let us make sure we did not set HD500 to 15 at the same time as resetting to All Ports...
5) Nope - Even more damning - the Port is listed as 'All' here, not 'iConnectAudio4+ DIN' as it is in the Devices list.