Need Help W/ Some Glitches

Lately, Wynncraft has been acting up a bit. I have experienced some gameplay issues affecting my time on the server, and am looking for help getting them resolved. There are 2 I want to focus on.
1. Random map glitches. As in, I will fall out of the world or the game will lag tremendously.


2. Server starting is bugged. When I join Wynncraft, half of the time it will spam me with the message:
"Flying is not enabled on this server"
And then it will restart the server, over and over, until I close Minecraft.



I have tried numerous things to fix these. I have restarted my computer, freed hard drive space, have cleared my DNS cache, restarted Minecraft, asked people on the server, and many more.
Any help to fix these would be appreciated.
Thanks!