Keybow 2040 uart dead

I wanted to use the Keybow 2040 keypad to play short tunes from an SD card via a I2S device. Unfortunately since not all pins are broken out I wanted to play with pico 2040 board to do the SD card and I2S stuff and getting the commands from Keybow via UART. All is well except that I just cannot get the UART to work in the Keybow. What ever I do nothing is received on the receiving device.

I now have a simple circuitpython code to just send one message / second and other receiving it. When testing with two pico boards everything works ok. Scope also shows signals. But with Keybow there is nothing. Nothing sent at all. Funny thing is that if I reverse the code so that I send from a pico board to the Keybow I do receive data. So it seems that the TX pin is dead. Could it be? Everything else seems to work.