Did I just answer you on the PN forum?
For me, the odd extra yellow pixel means almost nothing: 1% of pings being delayed by 1ms will cause that. That can happen in just about any router, anywhere.
The fact that the blue pixels have not increased tells you that the average delay has stayed the same - so over 50% of pings are getting through without even a 1ms delay.
The smaller yellow spikes definitely say things are getting busier - but without a similar change in blue, it still applies to only a small minority of packets. It is easy to cause this effect just by using the connection. Tall yellow spikes seem to become visible when you run a speedtest, because that delays a few ping packets badly, but the test is over before it can affect the average by much.
In days gone by, the 9-10pm busy hour would be highlighted with a broad yellow peak, of perhaps 10-20ms extra, with a small increase in blue. That, to me, is much more of a sign of broader congestion... yet you show no sign whatsoever.
The red packet loss is different. It indicates either a discarded packet due to congestion, or a packet that was lost due to a noise burst on the DSL connection.
However, packets discarded because of congestion will also be surrounded by packets delayed by the same congestion ... so you'd be bound to see much more yellow, and almost certainly some blue too.
This one looks more like my expectation of congestion:
(live graph, so what I'm looking at will disappear in 24 hours)
Happy New Year to you too...