why ipv4-fasttrack-active set to no ?

Yes. :sunglasses:
CCR support
conditions are met

Does the position of the rule important ? (for me dummy=0, fasttrack=1)

/ip firewall filter> print
Flags: X - disabled, I - invalid, D - dynamic 
 0  D ;;; special dummy rule to show fasttrack counters
      chain=forward action=passthrough 

 1    chain=forward action=fasttrack-connection 
      connection-state=established,related log=no log-prefix="" 

 2    ;;; Accept all establish related connection
      chain=input action=accept connection-state=established,related log=no 
      log-prefix="" 

 3    ;;; Drop all invalid connection
      chain=input action=drop connection-state=invalid log=yes log-prefix="" 

 4    ;;; Drop all invalid connection to forward
      chain=forward action=drop connection-state=invalid connection-type="" 
      log=no log-prefix="" 

 5    ;;; Accept all establish related connection to forward
      chain=forward action=accept connection-state=established,related 
      connection-type="" log=no log-prefix="" 

 6    ;;; VOIP
      chain=forward action=accept protocol=tcp src-address-list=Peoplefone 
      in-interface=combo1 src-port=5060 log=no log-prefix="" 

 7    chain=forward action=accept protocol=udp src-address-list=Peoplefone 
      in-interface=combo1 src-port=5060 log=no log-prefix="" 

 8    chain=forward action=accept protocol=udp src-address-list=Peoplefone 
      in-interface=combo1 src-port=8000-30000 log=no log-prefix="" 

 9    chain=forward action=drop protocol=tcp in-interface=combo1 src-port=5060 
      dst-port="" log=yes log-prefix="" 

10    chain=forward action=drop protocol=udp in-interface=combo1 src-port=5060 
      dst-port="" log=yes log-prefix="" 

11    chain=forward action=drop protocol=udp in-interface=combo1 
      src-port=8000-30000 dst-port="" log=yes log-prefix=""