Enable tcp_bbr for your debian/ubuntu (tested on debian)

tcp_bbr.sh

#write config
echo "net.core.default_qdisc=fq" >> /etc/sysctl.conf
echo "net.ipv4.tcp_congestion_control=bbr" >> /etc/sysctl.conf

#apply config
sysctl -p

#set fq to eth
sudo tc qdisc replace dev eth0 root fq pacing

#Backup write config: (Also affect ipv6 tcp)
echo bbr > /proc/sys/net/ipv4/tcp_congestion_control

#Check current status: 
cat /boot/config-$(uname -r) | grep BBR

#if the result shows "m", it works