[Elecraft] CW Monitor audio lost on Line Out after upgrade of FW release in my K3

[Classe Bergman]

Hi,
Today I upgraded my K3 with new FW, I was using 5.38/2.86 and I installed
5.50/2.87
I then discovered that the CW Monitor audio was lost on Lin Out. First I
tought  that some settings was messed up but could not find anything. I
then downgraded my K3 to 5.38/2.86 and the CW Monitor audio was back ! I
found that if I change settings from LIN OUT = "Nor"as I normaly use  to
"=Phones", the CW Monitor audio comes back. So something have changed the
function of Line Out audio in the new FW release.
Since all audio levels follows the Front AF vol  when using  "=Phones" this
mess up levels to my soundcard in the PC. My K3 s/n 1464 have the old KIO
board without USB interface

Is this a known bug ( or maybe a feature ..) ?

73 Classe SM3GSK