[mbed-tls] ECDHE Shared Secret is computed differently

Hello , We are trying to perform an ECDHE key exchange between two devices running on different platforms.[one on Linux and another on RTOS] Both the devices use the same code to compute the ECDHE shared secret. The peer public parameters are exchanged in the base64 format and passed to the functions correctly , but the final shared secret computed seems to be different on both ends. We have tested the same source code on Visual studio and found working. I have attached the source files

Could you please comment on why the computed shared secret are different on both the ends?

Thanks, LIJIN T V