So it seems my issue has to do with Viber detecting my phone is rooted. Funny thing is, my phone has been rooted from day 1. I've been using Viber almost as long. I'm guessing either Viber added root detection recently, or the recent installation of Xposed triggered something. Solved my issue with RootCloak. Now I can legitimately purchase stickers again. (Yes, I've chosen to use my root powers for good and not evil

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