Windows 8.1 Login IDs

When I login to my various internet accounts, I always select "Remember my ID" (or equivalent), yet the next day if I go to the web sites, my IDs are gone and I must re-enter them.  Why would this be?  I do not run other maleware/scanning software, but I do a full NIS scan every night.  I do have 3rd party cookies blocked, but I have these web sites in my "Trusted Sites" list.