Could you please provide your STM32CubeMX configuration file (.ioc) so I can verify your setup? Additionally, if possible, please share your schematics and project files. This will help me pinpoint the root cause of the issue and guide you toward a solution.
Attached below is a working Ethernet project using LwIP and FreeRTOS v1 on the STM32H753ZITx. You can use theCompare Projectstool in STM32CubeMX to compare this working project with your configuration, identify differences, and update your settings accordingly. Similarly, you can compare the rest of the project files to spot any discrepancies.
Although this example is a UDP echo server, you can certainly modify it to fit your specific needs. For a detailed walkthrough of the steps, please refer to the article linked below.
Do you have any updates regarding your issue? Were you able to resolve it? If so, please remember to mark the response that helped you as a solution by clicking Accept As Solution. This will help other users benefit from the information as well.