Minecraft: Is this a bug or a server problem?

I was playing around on my server and i saw this

https://imgur.com/a/ICfM7MN

Does anyone know what caused this? I've tried to relog on the server but its still there, tried to restart server still nope.
I used the plugin EpicWorldGenerator it seemed to work fine, but this chunk didn't seem to load and i can't find what would've caused it not loading.
My server specs are pretty fine 2GBs of RAM and an Intel processor.


Any help would be appreciated thanks,

If you can get into this hole than its server side. If not its client side that client is not synced with the server (maybe low TPS)

It's not letting me through it, so meaning it is client side. Do you know how to fix this?

probably because you converted a older versions map into another?