CCleaner not cleaning whats app cookies and a few more

For whatever reason, only on my desktop running Windows 7 x64, CCleaner leaves a few cookies which I don't use. The most baffled is the whatsapp cookie (web.whatsapp.com) where I only used it once but it keeps coming back.

Has anyone else experienced this issue?

Which web browser is that cookie stuck in?

You may want to try the cleaning ability that's built into the web browser to see if it can get rid of it.