Hi there, and apologies in advance if this is in the wrong forum.

I'll get right to the point. A few months, if not 1 year ago I signed up for the Telecom VDSL Internet package. As such, I was forced to use the supplied Router, the TG589vn v2. The first week was hell, but things sorted themselves out after that and I had perfect internet for months on end.

I recently upgraded my computer and reconnected to the Router. A week in I'm getting excessive latency spikes to the TG589vn v2 Router. I'll provide a copy paste of those pings below. My issue is, I had no issues on my older computer, and now this issue is effecting everyone in the house, even laptops which are less than 5 meters away from the Router. 

Just to make things clear, I got a replacement modem and plugged that in. It didn't solve anything. There is a cordless phone near the Router, but it never caused issues with previous Routers, or during the months that I actually had good internet. I've tested an ethernet connection and that has shown that the pings don't spike at all, though I checked last week.

Pinging 192.168.1.254 with 32 bytes of data:
Reply from 192.168.1.254: bytes=32 time=1228ms TTL=64
Reply from 192.168.1.254: bytes=32 time=1228ms TTL=64
Reply from 192.168.1.254: bytes=32 time=1840ms TTL=64
Reply from 192.168.1.254: bytes=32 time=1230ms TTL=64
Reply from 192.168.1.254: bytes=32 time=1227ms TTL=64
Reply from 192.168.1.254: bytes=32 time=1228ms TTL=64
Reply from 192.168.1.254: bytes=32 time=1227ms TTL=64
Reply from 192.168.1.254: bytes=32 time=1842ms TTL=64
Reply from 192.168.1.254: bytes=32 time=321ms TTL=64
Reply from 192.168.1.254: bytes=32 time=535ms TTL=64
Request timed out.

I'm stumped. It makes no sense that this would happen. Any help would be greatly appreciated.