Despite the board.h has the correct settings:
#define BSP_USING_ETH
#ifdef BSP_USING_ETH
#define PHY_USING_LAN8720A
// #define PHY_USING_DM9161CEP
// #define PHY_USING_DP83848C
#endif
the stm32f4xxhal_conf.h contains wrong parameters generated for the last driver in the list, in section 4.
they must be
PHY_SR ((uint16_t)0x001FU)
PHY_SPEED_STATUS ((uint16_t)0x0004U)
PHY_DUPLEX_STATUS ((uint16_t)0x0010U)