What happens when you visit the same sites over and over again is that your web browser may try to access cached data that has timed out. That makes your browser think that you are signed in already, but the website things that you need to sign in again. This can cause a multitude of problems with the access to the site that can cause problems like blank pages, pages that look like a bunch of colored text, etc.
Periodically clearing your cache and cookies can help with this. Honestly, this is not something that I remember to do on a regular basis on its own, but it is one of the things that I try when troubleshooting a problem accessing a web page. The instructions are below, inserted from: https://support.google.com/chrome/answer/95582
Delete all your data
You can choose any timeframe for deleting cache and cookies, but generally I choose "the beginning of time." You will also have options for what types of browsing history to clear. I generally choose the top 4 boxes and that solves the problem most of the time.