MSP430F5437: Using BSL-RX and TX pins as regular UART on Replicator REP430F

Part Number: MSP430F5437
Other Parts Discussed in Thread: REP430F, SN74LVC1T45

Tool/software:

Hello, 

My intention is to complement Replicator REP430F with custom code that allows communication and programming replicator with desired image.
My problem is that I cannot bring UART to work. I haven't found any notes that BSL-RX and TX pins cannot be used for user application as UART line.
Currently, I use Replicator430F from slau320 repository as a base code.

Here is my UART code:

#include "Config430.h"        // High-level user input
#include "driverlib.h"
#include "debug_log.h"

#ifdef MCLK_18MHZ
    #define MCLK_FREQ 18000000 // 18 MHz
#else
    #define MCLK_FREQ 12000000 // 12 MHz
#endif

#define UART_BASE USCI_A0_BASE
#define UART_BAUD_RATE 115200

bool is_init_done = 0;

void Debug_UART_Init(void)
{
    if (!is_init_done)
    {
        GPIO_setOutputLowOnPin(GPIO_PORT_P2, GPIO_PIN0);
        // Configure UART pins: P3.4 = UCA0TXD, P3.5 = UCA0RXD
        GPIO_setAsPeripheralModuleFunctionInputPin(
            GPIO_PORT_P3,
            GPIO_PIN4 | GPIO_PIN5
        );

        // Calculate baud rate settings
        uint32_t clockSource = MCLK_FREQ;
        uint32_t baudRate = UART_BAUD_RATE;
        uint32_t n = clockSource / baudRate;  // ~ 104.1667
        uint32_t brdiv = n / 16;              // = 6
        uint32_t remainder = n - (brdiv * 16); // ~ 8.1667
        uint32_t firstMod = (uint32_t)( ( (float)remainder / 16.0 ) * 16 + 0.5 ); // ~ 8
        uint32_t secondMod = 0; // Approximation for minimal setup

        // Initialize UART configuration structure
        USCI_A_UART_initParam uartParams = {
            .selectClockSource = USCI_A_UART_CLOCKSOURCE_SMCLK,
            .clockPrescalar = 6, // brdiv,
            .firstModReg =  8, // firstMod,
            .secondModReg = 0, // secondMod,
            .parity = USCI_A_UART_NO_PARITY,
            .msborLsbFirst = USCI_A_UART_LSB_FIRST,
            .numberofStopBits = USCI_A_UART_ONE_STOP_BIT,
            .uartMode = USCI_A_UART_MODE,
            .overSampling = USCI_A_UART_OVERSAMPLING_BAUDRATE_GENERATION
        };

        // Initialize UART module
        if (STATUS_FAIL == USCI_A_UART_init(UART_BASE, &uartParams)) {
            // Initialization failed
            while(1);
        }

        // Enable UART module
        USCI_A_UART_enable(UART_BASE);

        // Clear any pending interrupts
        USCI_A_UART_clearInterrupt(UART_BASE, USCI_A_UART_RECEIVE_INTERRUPT);

        is_init_done = 1;
    }

}

void Debug_UART_Log(const char* message)
{
    while(*message)
    {
        USCI_A_UART_transmitData(UART_BASE, *message++);
    }
}

This code is added after general MCU initialization from file Replicator430.c

void runProgramm(void)
{
    //! \brief Data pointer
    word p;
    //! \brief Buffer, used for memory read with ReadMemQuick()
    word ReadArray[0x40];

/*------------------------------------------------------------------------------------------------------*/
/*  1. | Initialize host MSP430 (on Replicator board) & target board                                    */
/*------------------------------------------------------------------------------------------------------*/    
    
    InitController();                     // Initialize the host MSP430F5437
    
    ShowStatus(STATUS_ACTIVE, 0);         // Switch both LEDs on to indicate operation.

    Debug_UART_Init();
    Debug_UART_Log(test_msg);

What I tried:
1. I verified that clock works and set to 12 Mhz(choose in config file), by enabling test through the pin and checking with logic analyzer.
2. I tried to use internal UART loop back and it works, I see register values change when I try to TX, RX register is populated with same value, if I enable interrupts, they also trigger.
3. I set level shifter SN74LVC1T45 (REP430F schematic), to output process signal B->A direction P2.0 LOW output. see document REP430F user guide for schematic.
4. I connected FTDI serial cable to check output and I see nothing. I cannot logic analyzer and it also doesn't register any signaling.

Any help would be appreciated!