Posted by not done it yet on 24/02/2019 12:37:56:
What is a cookies? 
I know nothing about any special settings.
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A cookie is a file stored on your computer. They are used by Browsers and Web servers to store information within a session or across several sessions. Information like: are you already logged in, have you visited this website page before, and the content of a partly filled out a form. Loads more reasons – used for any situation where a web browser / web site needs to remember something. Although they can be 'persistent' cookies usually come with a time limit, after which they are deleted. Can cause "interesting" effects if your computer's clock is wrong.
Normally cookies aren't of interest to the user but there are exceptions.
First, cookies are a security and privacy risk. Consequently your Browser and any AntiVirus or privacy software you happen to be running are deeply interested in them. They have settings that block or delete cookies believed to be intrusive.
Secondly, all computer systems have limits. The cookie specification says your computer & browser should store at least 300 cookies of at least 4000 bytes each, and allow at least 20 cookies per server. If your computer runs out of cookie space, it may behave oddly. For example: you login to a website, and the website sends you a cookie confirming that. Then the server checks the cookie to see if you are logged in for whatever the lifetime of the cookie is. If your computer runs out of cookie space, or an anti-virus, anti-tracking, privacy , or speed-up program deletes the cookie, you are no longer logged in.
Thirdly, sometimes cookies get corrupted. This can cause much weirdness.
Everything you need to know about cookies here
Very likely you don't know much about your system settings, there are thousands of them. Most are set by software which is great until something goes wrong. It can be hard to pin down cookie problems. Several different things mess with them and they can be damaged, perhaps by a network problem.
May be worth telling your browser to clear cookies because doing so should fix space and corruption problems. The downside is it will also have you re-entering stuff again. How clearing out is done varies by Browser. Firefox hides it away under Menu->Library->History->Clear Recent History. Plenty of info on the web about how other browsers do it. On Windows, software like ccleaner will clean cookies and it may be easier to use.
The other thing that might help is switching to another browser: it has it's own cookie space, which could be clean.
Dave