Hi Gergely,
It sounds like the PoE functionality is working as the power is being delivered to the MCU after successful detection and classification? Is the MCU being powered by PoE via DCDC converter? Is the converter stable? The power and data should…
You should use an ethernet transformer that is rated for POE and is also compatible with your ethernet PHY (consult your ethernet PHY datasheet or supplier for a recommendation which is POE compatible). H2019NL is used on TPS2375EVM (see schematic below…