Can confirm this as well, during the day i get put on London/Amsterdam/Frankfurt servers and in the evenings i end up on Belgium or Finland (falls under Belgium region now) and the game is horrible to play.
From CT to Finland with Google transit is 230ms, i find when playing on NA it is also smoother.
You can notice the difference in the evening when you get tossed onto a Frankfurt or Amsterdam server.
I'm not a fan of WS's upstream's routes / latencies past London. In some cases certain countries have 200ms or more latency when they're a short hop from London. I've found using a service like ExitLag or VPNGame actually gives me between 140-170ms ping to pretty much any Apex server in EU constantly. It also gives 130-140ms ping to Singapore, though GCE servers seem to be extremely unstable / prone to packet loss for some reason, or I'd play there all the time.