Disable' vlan_filtering' option autou pdation in network file

i am using openwrt version '19.07-SNAPSHOT'
i am trying to disable 'vlan_filtering, but it keeps getting its default value '1' immediately after editing 3secs,
i am not able to track from which file/script its keep getting updated , any idea to stop its auto updation.

any suggestions ll be helpfull. thanks you in advance