Cannot load spectrum website or its webmail without clearing cache

Yesterday I could not load spectrum.net or my spectrum webmail (I have gmail but mainly use webmail). I called spectrum and they said clear your cache on Firefox, which I did and then it worked. Today I ran into the same problem and tried clearing the cache again. I used Firefox private window to view my webmail (both yesterday and today) but I couldn't log out today; spinning circle (I closed the window and could log back on the next time). Yesterday I could log out using the private window. I don't understand what is going on because I didn't have this problem just several days ago. Thank you. Laurel Sheppard