Why is CCleaner causing my computer to forget that I was signed in after I close it?

Good news that you have managed to work things out. It can be infuriating when something like that happens.

Don't worry about posting about it, you did it in a polite manner and we were glad to discuss it with you.

Feel free to post again should you have anything else to bring up notinfallible :)

And a belated welcome to the forum :)

Glad you got that sorted! :)