If you are allocated 192.168.1.100, then that can be allocated priority 1.
Then from 192.168.1.101 to 192.168.1.199, can be allocated a lower priority. Bear in mind that the guest wireless network is allocated priority 5.
The guest network is useful if you have visitors.
@Oddius09 though I agree with you about DNS servers that is not the OP's problem.
DLM has taken action on the line most likely due to the number of resets done with/without his knowledge. This has caused an increase in latentcy and noise margin in an attempt to stabalise the line by DLM.
At present his RTT to 188.8.131.52 is 16-18ms which is about right based on his hub stats.
Like many who are unfamiliar with networks, diagnostics (no disrespect to anyone intended) and interpretation of tracerts and pingplotter, he's still fixated on the ping spikes en route which are immaterial to the end result.
Check the endpoint first and only if there is a problem there work backwards in the tracert/pingplot.
Depending on your connection it can be set to interleaved ,or fasthpath this is set by BT will also affect you latency. interleaved will give you higher latency. You also appear to have a bridge tap which can cause issues.
Yes networking is one of those dark arts, I would start from the games server end as well.