So I have had an official reply from
"Thank you for your email, and I am sorry you are having trouble with CCleaner for macOS.
Please allow me to clarify that this is the expected, and largely unavoidable, behaviour in this version of the software, however. This occurs when you are Cleaning ‘Safari Cookies’, 'Logs' or ‘Directory Service Cache’, so if you have both of those rules checked when running a clean you will be asked twice to enter your password. We’re doing this so that we can clean things properly and thoroughly, as you’d expect from CCleaner
Previous versions of CCleaner for macOS would be unable to secure the needed administrator permissions to thoroughly clean these areas of the system due to not being able to ask for this password, due to recent changes in macOS' security policies.
Please note that this must be done in the case of the Safari Cookies even if Safari is not opened, due to the fact that these files are protected by the macOS operating system itself.
Unfortunately, as this is a response to changes made in the operating system itself, there is no way to 'fix' this, short of unchecking the Cleaning Rules that prompt this, which would then prevent CCleaner from being able to clean those areas of the system at all.
Please let me know if I can do anything else to help you out!
xxxxxxx | CCleaner Support - Tucson, AZ"
So in short, apparently previous versions of Ccleaner only "pretended" to clean 'Safari Cookies’, 'Logs' or ‘Directory Service Cache’