because it's supposed to be a developing issue, i don't have this thing will my other server hosted on the same VPS and using the same Phar
Try it without using any plugins. If you experience the same issue, Try one plugin at a time, until you have the problem. Pretty much, you need to find exactly what the problem is. Sometimes, it might not be a Plugin issue. Sometimes it might not be a PocketMine issue. It could be a VPS Issue. Or how you set the configs in the VPS.