If you are using John's "GL Catalog" app it should be able to download the latest magazines just fine, but
I think it currently only builds the folders when first run, so it will probably just show those months that were available when the app was installed. You might try fully removing it (including manually removing the .ldswebos folder from the device, and then using software manager to remove the app), then re-downloading the .ipk file (in case any changes have been made since you last downloaded it) and finally installing it again with WebOS Quick Install or Preware. Basically, follow the same process suggested in another post: https://tech.lds.org/forum/showthread.php?8413-HP-Touchpad-apps&p=81339&viewfull=1#post81339
Don't forget to report back whether that works for you or not, for the benefit of others who might have the same question.
Note that doing the above removes all the previously downloaded content from GL Catalog, so the app will need to re-download the scriptures, etc, again as you browse to them. There may be an easier way to force the app to rebuild the index but I'd have to look at it closer.
Also note that it's possible to install both the Gospel Library app and the GL Catalog app at the same time. They are separate from each other and currently work a bit differently. I actually find it's sometimes nice to have them both open at the same time as that provides an extra window to look up something else and be able to quickly flip back and forth.