Is it normal condition that "hAP lite" unexpectedly goes into reboot after using zmap?

Summary:
if i run zmap on host connected to interfaces that resides on bridge and than srcnat’et to wan => RouterBoard goes in to reboot…
(zmap runing against ip resided in wan segment)

Simple configuration:
one bridge (3 port’s)
one wan (1 port)
one NAT: /ip firewall nat add chain=srcnat out-interface=ether1-gateway action=masquerade
a few standart firewall rule:
/ip firewall {filter add chain=input action=accept connection-state=established,related
filter add chain=input action=drop in-interface=ether1-gateway
filter add chain=forward action=fasttrack-connection connection-state=established,related
filter add chain=forward action=accept connection-state=established,related
filter add chain=forward action=drop connection-state=invalid
filter add chain=forward action=drop connection-state=new connection-nat-state=!dstnat in-interface=ether1-gateway}
zmap command: zmap -B 10M -p 80 -o jus_test_80.csv x.x.0.0/16

Any suggestion?