Now Confirmed!
In above picture you can clearly see that Amex Platinum is in fact generating 5x on a MileagePlus X (MPX) purchase. It can take quite some while before you get your 5x and that might be one reason why this deal isn’t being noticed. On 7th of July I purchased $25 Amazon gift card but I had to wait till 21st of August for 5x to show up in MR statement page.
That said, PRG should also earn 3x on MPX. While I don’t have first hand experience of 3x earning, I think it is fair to trust DP of 3x earning.
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Originally posted on Jun 26, 2017
For a while now I’ve seen scattered reddit DPs of 3x and 5x MR earning on MPX for PRG and Platinum cards respectively. At first I thought these were false DPs but the repetitive occurrence of these DPs across multiple platforms hints otherwise. However, the issue with these reddit DPs is that I can’t find them anymore. I suspect they’ve been deleted and I now feel that I’ve been too unwise to not screenshot them.