I have had Pokedex 3D since the day I got my 3DS, and I've been hard at work trying to complete it. However, I stopped recieving Pokemon about a month ago, and I haven't gotten any moe since. I still have quite a few pokemon eluding me, and most of them aren't legendaries. Is anyone else having this problem?

ever since the update for Pokedex 3D that same day I received at least 6 new ones and ever since I haven't received any - I only have 106!

You have to scan QR codes to get the ones you don't have yet. They start to appear again after scanning.
Codes

How do you scan the QR codes?

Open your Pokédex 3D, go to the options menu (top-right) and there should be the AR viewer option. Then point the camera on those codes I gave you and it should register those Pokémon. The ones you already have are fully colored and ones you don't appear as black silhouettes. After you've scanned them, you should receive those scanned Pokémon you didn't have yet by the same way as usual (some legendary Pokémon appear in your dex instantly after scanning).