Google Play Games pop-up not appearing for PvZ 2.

Hello! I've noticed that the Google Play Games pop-up, the one that tells me I've unlocked an achievement and tells me Play Games is connected upon boot up, is not appearing, and I would like for it to appear, because I am currently getting all the achievements for Plants vs. Zombies 2, and I like having the pop-up instead of needing to go back to the main screen or exit out of the game to check achievements.

This pop-up works find on other apps, and just seems to be an issue with Plants vs. Zombies 2.