I saw this glitch from the time I upgraded to 1.15 yesterday. The problem is that the right hand of my player moves two times when I right click and place a block, I have an internet connection with normal speeds which do not change i.e. 1Mbytes/sec plus, so I think there is not any problems with my network, and as it also appears everytime. The hand of my player doesn't shake two times when I break a block.
I have tried doing the following:
1) Tried 2 server software, namely Vanilla and Spigot/Bukkit
2) Reset the server plenty of times
3) Tested in single-player Minecraft, the glitch doesn't appear
4) Also saw the Logs and the Console, but no errors
5) Tested this using a different Aternos account, but still the glitch appears to be there
Please fix this glitch as soon a possible if it is a real glitch, and please let me know why it is happening.