IGMP SNOOPING configuration getting erased.

I have configured my fortiswitches for IGMP-snooping. but after 2-3 days streaming stopped. when I check, the configuration I did was not their. both from Core and distribution switches... 

****Core switch Config ---> on MCLAG Peer

config switch vlan

edit 10

set igmp-snooping enable

set igmp-snooping-proxy enable

set igmp-snooping-fast-leave enable

set igmp-snooping-querier enable

MCLAG PEER SWITCH

Distribution Switch.

config switch vlan

edit 10

set igmp-snooping enable

set igmp-snooping-proxy enable

set igmp-snooping-fast-leave enable
set igmp-snooping-querier disable

end