Incorrect / wrong warning messages in the server console

Incorrect output messages in the server console

When starting a server there are (most likely incorrect / unnecessary) warning output lines:

[main/WARN]: Ambiguity between arguments [teleport, destination] and [teleport, targets] with inputs: [Player, 0123, @e, dd12be42-52a9-4a91-a8a1-11c01849e498]
[main/WARN]: Ambiguity between arguments [teleport, location] and [teleport, destination] with inputs: [0.1 -0.5 .9, 0 0 0]
[main/WARN]: Ambiguity between arguments [teleport, location] and [teleport, targets] with inputs: [0.1 -0.5 .9, 0 0 0]
[main/WARN]: Ambiguity between arguments [teleport, targets] and [teleport, destination] with inputs: [Player, 0123, dd12be42-52a9-4a91-a8a1-11c01849e498]
[main/WARN]: Ambiguity between arguments [teleport, targets, location] and [teleport, targets, destination] with inputs: [0.1 -0.5 .9, 0 0 0]
[main/INFO]: Loaded 0 recipes
[main/INFO]: Loaded 0 advancements

Then the usual logging continues fine:

[Server thread/INFO]: Starting minecraft server version 18w07a
[Server thread/INFO]: Loading properties
[Server thread/INFO]: Default game type: SURVIVAL
[Server thread/INFO]: Generating keypair

< etc >

The percentage (progress) for generating / loading the terrain is printed incorrectly too

After the initializing (checking version, loading configuration, loading advancements, etc.) the terrain (world) loads "instantly" and there is spam of incorrect / repeating lines in the output:

[12:46:13] [Server thread/INFO]: Preparing level "world"
[12:46:13] [Server thread/INFO]: Reloading ResourceManager: Default
[12:46:13] [Server thread/INFO]: Loaded 517 recipes
[12:46:13] [Server thread/INFO]: Loaded 560 advancements
[12:46:13] [Server thread/INFO]: Preparing start region for level 0
[12:46:14] [Server thread/INFO]: Preparing spawn area: 0%
[12:46:14] [Server thread/INFO]: Preparing spawn area: 0%
[12:46:14] [Server thread/INFO]: Preparing spawn area: 0%
[12:46:14] [Server thread/INFO]: Preparing spawn area: 0%
[12:46:14] [Server thread/INFO]: Preparing spawn area: 0%
[12:46:14] [Server thread/INFO]: Preparing spawn area: 0%
[12:46:14] [Server thread/INFO]: Preparing spawn area: 0%
[12:46:14] [Server thread/INFO]: Preparing spawn area: 0%
[12:46:14] [Server thread/INFO]: Preparing spawn area: 0%
[12:46:14] [Server thread/INFO]: Preparing spawn area: 0%
[12:46:14] [Server thread/INFO]: Preparing spawn area: 0%
[12:46:14] [Server thread/INFO]: Preparing spawn area: 0%
[12:46:14] [Server thread/INFO]: Preparing spawn area: 0%
[12:46:14] [Server thread/INFO]: Preparing spawn area: 0%
[12:46:14] [Server thread/INFO]: Preparing spawn area: 0%
[12:46:14] [Server thread/INFO]: Preparing spawn area: 0%
[12:46:14] [Server thread/INFO]: Preparing spawn area: 0%
[12:46:14] [Server thread/INFO]: Preparing spawn area: 0%
[12:46:14] [Server thread/INFO]: Preparing spawn area: 0%
[12:46:14] [Server thread/INFO]: Preparing spawn area: 0%
[12:46:14] [Server thread/INFO]: Preparing spawn area: 0%
[12:46:14] [Server thread/INFO]: Preparing spawn area: 0%
[12:46:14] [Server thread/INFO]: Preparing spawn area: 0%
[12:46:14] [Server thread/INFO]: Preparing spawn area: 0%
[12:46:14] [Server thread/INFO]: Preparing spawn area: 0%
[12:46:14] [Server thread/INFO]: Done (1.014s)! For help, type "help" or "?"

If a player tries to join the server there is momentary freeze / hang, "Loading Terrain" is stuck on the player's screen for a while then everything continues fine until server restart, for example.