frequenty R0 with different POl error codes 4001 / 2025

i had problems with more frequent R0 for about 2 months by now. today since about 5 hours i have massive issues with very frequent R0, sometimes i d/c slowly over time where i'd start sending data again then go back to R0, somtimes i d/c very quickly.

most of the time i also have to wait multiple minutes (5+) till i can log back in cause the server thinks i'm still loged in.

i didn't switch my internet provider in years, didn't install anything new recently nor did i play with any router settings. i've tried to turn off anti virus and firewall, repluging the router and requesting a new IP, the problem persists.

i've received multiple different error codes uncluding but not limited to: 4001, 1160, 0011, 2025, 0250, 3001. 3100 some of them advising me to check my cables wether or not they plugged in properly; they are (i don't use wireless lan either).

other services and games that rely on internet connection work fine, its only FFXI thats acting up.

*edi*
just had another connection lost, Error code: POL-2059
Connection terminated or not available.
Please try connecting again later or check cables, networking devices, and network settings.