You dont't seem to understand what I said:
You don't need to clear the cookies in your browser and log back in. You only need to log in once solve the cloudflare captcha, then copy the cookies and paste them into your jDwonloader pw-field. When changing ip with vpn and you are not logged out, you can use the same cookies as with the ip before. The only thing you can do after ip change with vpn or router reconnect, is to go into account manager in jdownloader, right click on your recurbate account and click refresh.
For those too lazy to Google, or don't know any disposable mail providers: