There was a bug a loooong time ago where that happened.  It was resolved quite some time ago though.
Are you using the most current version of Access?

F5 should refresh the navigation pane.  But,  I would also run through the items on the Troubleshooter page.

That may be an indication of a bigger issue brewing.

Are they turned off there?

Or is it only new ones?

I've just seen appears in the navigation pane but it takes some time

Is it normal for it to takes that amount of time?

What is some time? A few seconds? A few minutes?

If you're just saving it to the backend on the local PC it shouldn't take very long, unless it was an import of thousands of records maybe.

I also have a problem with the date/time field, I can't input date except I have to change the date field to a number field and enter the date then switch it to date field again b4 it works

Is it doing this in just your database? Or if you make a new blank one does it do it too?