Hi, @Asharm11
From my side, some suggestion as following:
1. Check hardware LIN(LPUART instance) and software configure is the same or not
2. Baud rate
3. Hardware connect including: LIN, VBAT and GND
4. Check LIN transceiver configuration
4. If above all is correct, you can capture the LPUART RX and TX signals over oscilloscope. If oscilloscope have not anything signals, then the issue might be from hardware. If the RX line have signals, then check the LIN driver RX the data or not. This can set a breakpoint in LIN RX ISR.
BR
Tomlin