How to debug nDAX rx audio problem

Installed nCAT and nDAX on Ubuntu 24.04 and it _almost_ works
nCAT setup on slice A
WSJTX points to port 4532, able to change freq and tx
WSJTX sees audo devices flex.sliceA.rx and flexr.sliceA.tx
PAVUcontrol sees flex input and output devices "FLEX-8600M slice A {RX TX}"
WSJTX Tune button keys transmit and generates tone and power

BUT,
WSJTX sees zero rx audio level
pavucontrol device input audio level on flex.sliceA.rx is zero

SOME Debuggin Info,
starting nDAX causes rx audio to come out the radio's speaker
../nDAX -station FLEX-8600M -slice A -daxch 1 -log-level trace -source flex.sliceA.rx -sink flex.sliceA.t
able to control RF and AF levels in the speaker via rigctl level commands

SOME trace from nDAX startup

9:48PM DBG found PulseAudio server version version=15.0.0
9:48PM INF Waiting for station station=FLEX-8600M
9:48PM DBG Set thread to realtime thread="udp thread"
9:48PM INF Found Client id=0x1C8D4D87 uuid=EB10B458-ADA0-4F09-8644-5AB1B9F9B5E0
9:48PM INF Looking for slice slice_id=A
9:48PM INF Found slice slice_idx=1
9:48PM INF Enabled RX DAX stream stream_id=4000008
9:48PM INF Enabled TX DAX stream stream_id=84000000
9:48PM DBG Set thread to realtime thread="tx thread"
9:48PM DBG Set thread to realtime thread="rx thread"

QUESTION, does any of this lead to the source of the problem and either how to fix it or how to debug further?

thanks
jeff, wa1hco