[Elecraft] K3 microphone input selection

[Alan. G4GNX]

When I have two microphones connected to the K3, one in the front panel and one in the rear panel, I can select which one I want to use and whether bias is turned on for either or both, via the menu as expected.
If I select the rear panel microphone, it works as expected and the front panel mic is muted.
If I select the front panel microphone it works OK, but the rear panel microphone is also unmuted and transmission sounds like two voices at the same time, probably due to the two mics being out of phase.
Is there any way of selecting the front panel microphone only, with rear panel mic plugged in?
As both microphones are electrets, the only way I can think of getting round it temporarily is to turn the bias off on the rear panel mic, when using the front panel mic, which is inconvenient and not a ‘clean’ solution.

73,

Alan. G4GNX