Happens to me too on ocassions, it was particulary bad around at around the end of May, where I would log on for like 10 seconds and get kicked (same as you) and I would relog for 15 minutes until it finally worked.
I have the same issue. It is probably related to https://radar.cloudflare.com. You can look to ddos attacks at your country. If the total traffic is more than 0.60 you will probably have this issue, but only some people have this issue and I still couldn't comprehend the exact reason.