I did not try this with Vanilla Server but I can confirm with a Paper Server that the Vanilla Minecraft Client up to 1.11.2 has a problem with too fast packets.
I'm running the latest Paper on Debian in my local network. Around one third of the drops from broken blocks or dropped items disappears. The drops have no bounding box and F3+A doesn't help, they simply vanish, but reappear on relog and I can pick them up while they are invisible. External connections don't have this problem, just my Windows 10 Laptop with i7-4702MQ and Nvidia 760M GTX when connecting from inside the network with a 1ms Ping. After reading this issue I added a small 5ms delay to the Server network interface using the command "tc qdisc add dev eth0 root netem delay 5ms". Nothing else was changed in Client, Server or Debian. Since then, the problem never appeared again.
I did not try this with Vanilla Server but I can confirm with a Paper Server that the Vanilla Minecraft Client up to 1.11.2 has a problem with too fast packets.
I'm running the latest Paper on Debian in my local network. Around one third of the drops from broken blocks or dropped items disappears. The drops have no bounding box and F3+A doesn't help, they simply vanish, but reappear on relog and I can pick them up while they are invisible. External connections don't have this problem, just my Windows 10 Laptop with i7-4702MQ and Nvidia 760M GTX when connecting from inside the network with a 1ms Ping. After reading this issue I added a small 5ms delay to the Server network interface using the command "tc qdisc add dev eth0 root netem delay 5ms". Nothing else was changed in Client, Server or Debian. Since then, the problem never appeared again.