CCleaner closing again.

[Bastet]

CCleaner is removing the icon from the notification area again.
No settings have been changed.
Defender is set as default.

Windows 11.

[nukecad]

The icon in the notification area is put there by Windows if you have either Smart Cleaning or Automatically update CCleaner turned on.

Because they run as background processes Windows gives the running process an icon in the system tray (notification area).

Win11 changed how things are displayed on the taskbar/system tray so I'd suspect that this is Windows 11 removing or hiding the icon, see if this helps:
https://www.ghacks.net/2021/11/28/how-to-display-all-system-tray-icons-in-windows-11/

[Bastet]

Yes, both are selected. 
The icon shows but after a while disappears but it is not in the hidden icon area. 

[nukecad]

Having a look around the web disappearing taskbar and system tray icons does appear to be a know issue with Windows 11, it's been there since it was first released (and before).
It seems particularly prevelant with dual monitor set ups, but affects single monitors as well.

Apparently the March 2022 updates to Win 11 started it happening for many who hadn't seen it before then, maybe next weeks patch Tuesday may do something about it?

There are a few sites giving suggestions of what you can try, here's just one, but it looks like you may have to wait for Microsoft to fix it.
https://www.droidwin.com/fix-taskbar-icons-missing-in-windows-11/

 

[Bastet]

Thanks, although this is only affecting CCleaner. 
I have a laptop so not using a separate monitor.