Open a serial terminal on VCOM0 (primary USB serial port, UART30 on P0.06/P0.07). Do not use VCOM1 while the EB2 is attached.
Serial Modem logs appear on VCOM1 of the nRF9151 or nRF9151 SMA DK (UART1, P0.28/P0.29). Keep that terminal open alongside the host console when bringing up the link.