[nftables 0.9.2 | kernel 4.19.93] dropping ct state untracked stops ipv6 connectivity

[ѽ҉ᶬḳ℠ <vtol@xxxxxxx>]

This works (i.e. ipv4 and ipv6 connectivity)

table inet filter {
        chain input {
                type filter hook input priority filter; policy drop;
                ct state established,related accept
                ct state invalid drop
        }

}

This cuts ipv6 connectivity entirely (ipv4 connectivity works)

table inet filter {
        chain input {
                type filter hook input priority filter; policy drop;
                ct state established,related accept
                ct state invalid,untracked drop
        }

}


It reproduces on each toggle: ct state invalid,untracked drop <-> ct 
state invalid drop (ct db/cache needs to clear in between toggling).
Enabled logging but nothing been printed that would provide a hint.

Is this something to be expected, and if so why, or is it a bug in 
kernel / nft?