Missing iCloud data via browser

I haven't opened the iCloud app on my PC in a while. Difficulty logging in .. repeated error message that it can't reach the server. If I keep clicking 'ok', it logs me in. But all apps - photos, mail, calendar are empty. When I access iCloud on my iPhone, it shows that I've used 3.6 GB of 5 GB, and that photos, drive, mail are all 'on'

Why can I not access my data via browser?