Your wording, I imagine;
that, along with a lack of context.
You haven’t given any system information that would indicate which Manjaro edition you’re using, for example. This makes it difficult for others to understand what you actually mean. No context.
Normally, one doesn’t:
You clearly mean something else, but it hasn’t been defined well enough by you for others to fully comprehend.
This is on you.
My best guess (from your original description) is that you clicked a “Logout” icon in your menu, or somewhere, and the resulting Logout screen (or dialog) doesn’t contain a separate “Sleep” icon.
But, this isn’t what you’ve told anyone; that’s not what “log out and use the sleep function” suggests; especially without context.
What comes to mind, however, is that (at least in Plasma) the shutdown/restart/logout screen options (several months ago) were reduced to only two icons per screen (one of the options mentioned, plus a cancel icon), depending on context).
Before that change sleep might have been included as an extra icon (totaling three icons per screen), but frankly, I don’t remember.
As I say, if you’re using Plasma, this might have been what you were trying to communicate; or it could be something else entirely.
Until you provide the requested System Information we can’t possibly know; and you clearly ignored the request for that information (from a Moderator in post #3).
So, you tell us, how are we to help you if you don’t put some thought and effort into your Support request?
As a Member of this forum since 2020, you should know better.
Your second post at least contains a little more information, and we might guess that your issue might be one of those already listed in recent Update Announcements under Known Issues and Solutions.
If you haven’t already, it may be worth reading through those items to find any that seem to fit your problem.
Please help us to help you.
At minimum, post your System Information, as requested.
Please take some time to familiarise yourself with Forum requirements; in particular, the many ways to use the forum to your benefit:
Required Reading:
Resources:
Update Announcements:
The Update Announcements contain update related information and a Known Issues and Solutions section that should generally be checked before posting a request for support.
System Information:
Output of the following command (formatted according to forum requirements) may be useful for those wishing to help:
inxi --admin --verbosity=8 --filter --no-host --width
Be prepared to provide more information and outputs from other commands when asked.
Regards.
Plus, not all forum Members are native English speakers.
This is something else for the OP to consider when composing a Support request.
Quite the conundrum, really.