I suspect that this may be the problem. I have to login every time I switch between alts, and I use a variety of connection methods and computers. These incude an Androd mobile, a netbook running Ubuntu, and a notebook with Windows 10. Most of the time I use public Wifi, or direct or tethered connections through the mobile. Sometimes I use the ethernet connection at a library. I doubt if I have to solve a Captcha once a month. Most of the time it decides I am human, and lets me in.