macOS isn't using my configured dummynet

I would like all UDP traffic on my localhost to have 1% packet loss, 5 ms propagation delay. I thought I could use macOS' built-in dummynet for this.

I ran at the terminal

sudo dnctl pipe 1 config bw 10Mbit/s delay 5 plr 0.01
echo "dummynet out proto udp from any to any pipe 1" | sudo pfctl -f -

sudo pfctl -sa and sudo dnctl list show the expected outputs (the rule seems to have been added).

DUMMYNET RULES:
dummynet out proto udp all pipe 1

00001:  10.000 Mbit/s    5 ms   50 sl.plr 0.010000 0 queues (1 buckets) droptail
    mask: 0x00 0x00000000/0x0000 -> 0x00000000/0x0000

Now I expect all udp traffic to be slowed.

I am developing a UDP app, testing it on localhost between a client program and a server program. The UDP traffic is clearly not having any dropped packets even though I would like to simulate 1% dropped packets.