Packet loss and high ping on FFXIV

I recently made a post some while ago wondering what was going on with the ping on a videogame that I play. The problem has unfortunately persisted and VPNs have not helped any. 

The issues only seem to happen at my residence. My mother (who lives about ten minutes away) has Xfinity as well and the same plan, but I haven't experienced any packet loss, lag, or high ping when connecting using her network. When I used PingPlotter at her residence the information I received looked very much the same. So I'm not sure it's a FFXIV issue anymore. 

Moreover, this issue happened incredibly suddenly. Prior to this I had no issues with Xfinity. I use a wired connection plugged in directly to the router. My mother had a combination modem/router from Xfinity.

Does anybody know what's going on? Please help!