If the MT3000 occurs this issue, please upgrade the firmware to 4.7.0-op24 and repeats the 2.4G WiFi (MSC portal).
Please try these commands in the SSH of router to temporary use:
mkdir -p /usr/share/nftables.d/chain-pre/mangle_prerouting
echo 'iifname sta0 counter ip ttl set 64' > /usr/share/nftables.d/chain-pre/mangle_prerouting/01-set-ttl-portal.nft
/etc/init.d/firewall reload
If the above operation still doesn't work, please execute the following command after repeater connected.
iptables -t mangle -A PREROUTING -i sta0 -j TTL --ttl-set 64