Hello Einmimiria,

As Middie states, it is unclear for me what to report to my ISP. The only thing I know is that this is happening and it only affects my connections to the Mana datacenter as I have never had this problem with either of the EU or NA datacenters and I have no character on another JP datacenter.

The least you can provide us with is the hostnames/ip-addresses the client is using, so the ISP can troubleshoot the particular connection. As I am mainly on PS4, it is really difficult to trace the problems myself, although I could put some routing machine between my PS4 and my modem and trace the traffic that way and send you the traceroutes. This will be a significant time investment though for a problem that seems to be in your datacenter or the connection of your datacenter to the internet.