[mbed-tls] Different performance from 2.6.2 to 3.6.2 for https file upload

Hello,

I recently updated mbedTLS library version 2.6.2 to 3.6.2. I am using the library to add https to Mongoose web server on a STM32H753 with FreeRTOS + LWIP.

2.6.2 was generated in a IAR project using STMCubeMX.

What I am noticing is that file transfer performance has gotten much worse. With version 2.6.2 it took a few minutes to transfer a file of around 33 MB, now with version 3.6.2 it takes around 15 min. What could this depend on? Attached is the configuration used for the two versions. The certificate for https is EC curve secp256r1.

Thank you