The 3-day free premium trial is misleading. You get only one free login, and even if you do not actually logout, you will not get a free trial after you move away from the browser. The non-premium free servers are also misleading, because after the first login you cannot log in again unless you pay. I used it for only a couple of minutes and it stopped hiding my ip after that.
Thanks for your report, that's not a bug. Free trial is given only ONCE per user per month. So if trial was removed, it means you or someone else used it from that IP.
As for FREE ones - they are free for life time without any payment. Could you please make sure that you are selecting the ones which label FREE? You can also send us email or open ticket, so we can better assist you. It looks like a bug in browser or the way you use tool... however, we will do our best to fix it in no time.
Funciona estupendamente pero hay que pagar! Le doy 5 estrellas porqué permite probarlo gratuitamente por 3 dias y ningún otro te da esta posibilidad. Tecnicamente es impecable : imagen muy nitida y fluida