MainStage MIDI Mono Mode Bug?

In the current version of MainStage (3.5.1), there appears to be a bug with MIDI Mono Mode. On some patches (Acoustic Guitar as an example), setting MIDI Mono Mode to "OFF" still does not allow the patch to be played polyphonically from any MIDI channel other than 1. Can anyone else replicate this issue?

This did not appear to be a problem before the change from ESX24 to Sampler. Interestingly, setting the MIDI Mono Mode to "OFF" DOES seem to turn off the MIDI Mode Pitch Range. IE, when MIDI Mono Mode is turned on, using the pitch bend for that instrument from any channel other than 1 results in a bend range of 48 (See attached image). Turning MIDI Mono Mode to off reverts the pitch bend range back to 2 (or whatever is the instruments normal pitch bend range). It still only plays monophonically, however.