Configurator for CAN controller has inaccuracy in calculating of time for one bit. If I set the values for CAN speed 500 kbit/s (bit time 2000 ns) then configurator show 2004 ns. If you calculate the bit time from BS1=8, BS2=3, prescaler=8 and APB=48 Mhz, the bit time is 2000 ns.
I also recommend to add to CAN configurator the calculated sample point. It's a very important value.