I am seeing the same thing. As soon as a server starts get the weird teleport messages. When a player joins it immediately starts throwing Can't keep up! messages and continues to do so entire time players are on server. Before 1.13.1 (1.12.2 and older) I might see these once in a great while due to map size growing or fast movement (i.e.. horse or boat) opening new chunks. Now I see it constantly – usually around 40 to 44 ticks behind however I get regular spikes to 100 and occasional spikes over 2000 ticks behind. Again, never saw this before 1.13.1. I didn't run 1.13, moved from 1.12.2 to 1.13.1 so can't speak to what would have happened there.
I run nogui so that doesn't figure in. I have tried numerous java parameters to adjust memory and memory allocation with no success.
I used to run 2 servers concurrently and FTP and TeamSpeak with no issues – now I have issues running just the 1 Minecraft 1.13.1 server with the others disabled.
Sever is dedicated Ubuntu Server 16.04 64bit Dual Core 2.8 GHz 4Gb Ram
I noticed that someone else mentioned this and the ticket was marked Invalid but I think there is a bug or something going on as there is a marked change in memory usage. I also notice my CPU usage spikes quite regularly much more than it used to.
As a note this happens while on land while not near an ocean so the new chunks don't seem to be the direct cause. I imagine there is another underlying reason.
Wow – now it works normally with Use Latest Version! Thanks.
Update – I uninstalled Java and reinstalled Java. Rebooted and then I uninstalled Minecraft and reinstalled it using the minecraft.msi file. It removed the 1.9 folder but did not replace it. In the launcher logs it says it is downloading 1.8.8 – NOT 1.9. That is where it fails at. The comment above about using Snapshot 1.9 (release 1.9) is correct – it works that way. Someone botched the loader command and is calling for 1.8.8 instead of the newest 1.9 version!
This also fixed my wife's and my buddy's issues!
Occurring on my system as well – Windows 7 64 bit and my wifes computer Windows 10 64 bit. Also my buddy is getting a bunch of weird Java argument errors now as well – Windows 10 64 bit. All of us were playing just fine yesterday with no issues up to 2240 hrs Central Time on 1.9.
Currently we are able to load up older editions – i.e. 1.8.9 including with resource packs.
It appears to only affect 1.9.
This is NOT resolved. Running vanilla server in 1.14.4 and my son started building a house out of black concrete. Server began experiencing lags every 20 seconds or so. Removed the concrete and lag went away. Definitely caused by concrete!