Waterrower S4 recognized but no data / Zwift App not working

[johnteh00]

fist of all: thanks so much for your efforts. great approach to make ind.rowing more fun!
after some trial & error i’ve got it set up on my banana pi pro board running armbian and my macbook via brew. Two issues arose though, that I can’t figure out:

sending test-data in debug mode via udp works. pi sends and the mac receives and forwards it via bluetooth.
when i plug in the waterrower and start the S4 is being recognized but no data is actually sent.

your setup doesn’t seem to work for me. No device is found in Zwift (set to companion app).
WR --(usb)--> pi --(udp)--> macbook ---(ble/wifi)---> phone+zwift_app --(ble/wifi)-> macbook+zwift

what does work—at least with test data—is involving my imac as BT sender and Zwift in BT mode (instead phone + companion app mode):
WR --(usb)--> pi --(udp)--> imac ---(ble)---> macbook+zwift

Suggestions anyone?