Did you happen upgrade your router? I ran to the similar issue (router started using hotspot data), it turned out that the new v4.5.16 doesn't have module iptables-mod-ipopt by default.
See more in [MT300] TTL override doesn't work in 4.5.0
Did you happen upgrade your router? I ran to the similar issue (router started using hotspot data), it turned out that the new v4.5.16 doesn't have module iptables-mod-ipopt by default.
See more in [MT300] TTL override doesn't work in 4.5.0