I commented before but forgot to mention the hardware I'm using. I used to be on 1.14.0 but now am using 1.14.1 and am still having this same issue. The specs of the server host I'm using is:
NVMe SSD drives.
Intel Xeon E5-1650v4 processors with a clockspeed up to 4.0GHz
and 10GB of DDR4 ECC 2133 MHz RAM
Server on idle will jump between 50% - 100% and stay there. Then when people log on it consistently stays between 98%-100% and we get all the lovely "server can't keep up" and large ms ticks. It can only handle 4 people on max now otherwise it becomes completely unplayable.
Can confirm that this is still an issue as of 5/11/2019 on version 1.14. My server is consistently at 100% CPU usage and randomly kicks people. It also randomly has the ticking issue and warns about lagging behind. "12.05 02:43:38 [Server] Server thread/WARN Can't keep up! Is the server overloaded? Running 2022ms or 40 ticks behind" It usually gets even higher than that. Occasionally it'll get bad enough where it crashes and I have to wait a while before even attempting at trying to start it back up.
Can confirm this also happens when riding horses and can cause the player to teleport into unwanted situations. 1.14.1