1.13 and above: Memory usage bug

Dear Mojang Team,

I tried to set up a Minecraft 1.14 Server and I discovered a huge Memory Lag Spike in the Minecraft Server Console. So I started to search for solutions on google but i didn't found anything. Afterwards I asked my friends if they could host the Minecraft Server on the version 1.14, > sadly, they had (and still have) the same issues as I do (my friend was on Windows 7). I found out, that it is in the version 1.13 and every version above.

What we tried: increasing the RAM (up to 16GB), decreasing the RAM (down to 512MB) and hosting the server on another operating system. We even bought a Minecraft Server (with 4GB),

but it was worse then ever and after some time, there was an error in the console called: ,,Can't keep up! Is the server overloaded?". The server software and the bought server made no difference.

Greetings, Jens Hendrik Geisen

My specs: 

GTX 980 Ti (6GB)

Intel Core i5 8600k

16GB 3000MHZ RAM (DDR4)