20.5.2.3.2 I2COV Status Flag

If another byte is received in the I2CxRSR register while the RBF status bit remains set and the previous byte remains in the I2CxRCV register, the I2COV status bit (I2CxSTAT1[6]) is set and the data in the I2CxRSR register is lost.

Leaving the I2COV status bit set does not inhibit further reception. If the RBF status bit is cleared by reading the I2CxRCV register, and the I2CxRSR register receives another byte, that byte will be transferred to the I2CxRCV register.