There also additional bugs relates iptables-nft as chain WANLOADBALANCE_OUT is not exist
https://github.com/vyos/vyatta-wanloadbalance/blob/70ee1319c20e083ab407d8a11faa44c74d05f084/src/lbdecision.cc#L312
vyos@r14# sudo nft list table ip mangle
# Warning: table ip mangle is managed by iptables-nft, do not touch!
table ip mangle {
chain PREROUTING {
type filter hook prerouting priority mangle; policy accept;
counter packets 851 bytes 179376 jump WANLOADBALANCE_PRE
}