Hang on, which are we talking about here? Google Play or Google Pay?
Google Play is an onine repository of nearly 3 million apps, some of which are free to use and others for which you have to pay. Google Pay is just one of those apps, which allows you to use your phone to pay in shops. (You've used both names in your question, so it's a bit confusing for people here).
Assuming it's Google Play, start by clicking on your Apps icon. If you see the same on your tablet as I do on my phone, you'll see 'A-Z', with a little arrow pointing downwards in th top left corner. Tap there and change 'A-Z' to 'Date'. That will show your apps with the most recently installed ones listed first. That might give you a clue as to what it is that's causing the problem.
This might also be relevant:
https://support.google.com/googleplay/answer/7205930