You beat me to the post! I have also been having issues with being kicked. I have the 'remember me' box checked, did that the first time I logged in. Haven't been pasting anything, just randomly get the message to leave the page and all data will be lost. Sometimes it will just refresh but most times it tries to reload and says the page can't be found. Very frustrating. I haven't been on this site for a few years but it is nice to see that it is still going strong!
You're not getting "kicked" or logged off; that's Cloudflare, the security software we've had to use since the DDOS attack.
You can either wait patiently, because when Cloudflare is active because of suspicious activity (including malware on your computer or ISP router) it scans and checks every single transaction between your browser and the server. That means every image or message you submit, every click you generate by using a button, etc, initiates a check.
If you can't wait, try the site at a different time; the bots essentially come in swarms. It will be better at another time.