I'm unsure why but all now working correctly.

Probably of no help but should anyone else have a similar problem, this is what I did following above post:

1. Ran CleanMyMac X then re-booted Mac - no change, Cookie still not opening at login
2. Ran CleanMyMac X to uninstall Cookie
3. Ran CleanMyMac X for a third time and did a full system scan
4. Re-booted Mac, downloaded and re-installed Cookie, entered licence details, selected Open at Login and received system message confirming Cookie opening at Login
5. Updated to the Beta version 7.4.3.1
6. Confirmed Cookie now appears in System Settings/Login Items and Extensions
7. Re-booted Mac and Cookie opened at login

Maybe put this down to "...one of those things?" but whatever, thanks for suggestions and advice, much appreciated.

Thanks for the prompt replies but as there are no other user accounts on the Mac I can't try that suggestion.

The Mac is still under warranty but I've drawn a blank in conversation with support as their approach is that as System Settings/Login Items and Extensions will allow addition and removal of other (Apple and non-Apple) applications then "...it would appear to be an issue connected to a third-party product".

Guess I'll have to try a full OS re-install over the weekend.

Yes.....and showing correct time it was installed.

Cookie still will not be added as a login item at System Settings/Login Items and Extensions despite using + key and selecting Cookie from Applications folder.

However, if I add another item - I chose Disk Utility - (a) this will show as a login item and (b) Cookie now appears in the list as well.

Re-booting the machine duly brings up Disk Utility but Cookie still not opening at Login and is now missing from the
Login Items and Extensions list.

I've also run Disk Utility, no errors reported.

Beta version 7.4.3.1 installed but exactly the same result, i.e. will not login on startup and System Settings/Login Items and Extensions still does not show Cookie as an "Open at Login" item or allow it to be added by using the + key and selecting Cookie.

Yes, 7.4.3

Never get updates from App Store so assume from your website.....

Running Sequoia 15.0.1 on M3 MacBook Air.

Cookie no longer opens at login.

Open Cookie at login selected in Cookie/Settings/Display

Open at login selected in Dock, Cookie Options

System Settings/Login Items and Extensions does not show Cookie as an "Open at Login" item. Using the + key and selecting Cookie will not add it to Login items

Have tried:

• multiple re-boots

• deleting ~/Library/Containers/Cookie and emptying Trash

• deleting Cookie and re-installing

Hopefully I'm missing something obvious but any suggestions gratefully received!

Updated Cookie to latest version since when it began to randomly close down.

Installed Ventura 13.0.1 and Cookie would not open at all.

I deleted Cookie, re-installed it from the SweetP site and it briefly opened before closing down and would not open again.

Now repeated this twice more with the same result.

Any advice much appreciated!