Recently Added Songs Not Appearing In 'Recently Added' Playlist

[Cyclone28]

I have lately noticed that my recently added songs won't appear in my "Recently Added" playlist automatically, on my iPhone 5. They tend to appear if there aren't any previously added songs already in that playlist but otherwise they don't want to show up. I've been syncing via USB connection from my laptop.
All appears well and good when looking at the "Recently Added" playlist on my laptop, as all the new songs are there.

Is there a simple fix to this or should I be taking it to an Apple shop for them to take a look at?
Also any suggestions would really help

 

[Just_Me_D]

I'm confused. You say that "previously added songs won't appear...", but "tend to appear if there aren't any previously added songs already in that playlist..."

 

[Jaguarr40]

I would assume by your statement that you have been able to add them before and have them show since you made the statement? Correct? Now no luck correct again?? If so can you back them up, remove them - all of them that are there now and try and add everything back including what you have been trying to add all at the same time and see if you can do it that way.

 

[Cyclone28]

I want the newly added songs to appear in the "Recently added"playlist. If I don't add any new songs for a week or two, the "recently added" playlist clears itself. So if I add new songs after the playlist has cleared itself, then they seem to show up in the "recently added" playlist just fine. But say after adding some new music yesterday, I buy a new CD and want to sync those songs to my iPhone today... This is where I've found the most recently added music to not show up in the "recently added" playlist, however they do appear in other general places (songs, artists, albums, etc.).
I've restarted my iPhone but no change.

 

[linsiris]

That's because the "recently added" playlist is a "smart playlist" which means that it has preset parameters that you can edit, like how many songs you want it to show, and that where added in certain span of time. For example this playlist usually shows songs added in the last 2 weeks, I prefer it to show the last 40 songs added in the last 6 weeks, so you can change the parameters if you want, all you have to do is go to iTunes on your laptop--> right click on the "recently added" playlist (or any other you want) --> edit smart playlist (which is usually the first option) and voil?. You can create and customize them as you wish.