Mine had worked perfectly on my P3 Adv for nearly 4 months, but last night after I removed the card to view the photos and videos on my laptop, it would not go back in. It makes an audible click, but it will not hold the card. I've tried 3 different cards, and none of them will seat properly in the slot. I'm not sure how those slots are made, but my guess is a latch of some sort must have broken. All 3 cards, incidentally, work perfectly fine in my laptop card reader.
I guess it's time to contact DJI support. Unfortunately, I bought mine directly from DJI so I'll have to ship it back for warranty repairs.