I haven't had mystery balance increases at Adobe Stock - but if you don't see it in the activity section, where exactly do you see a $60 "payment" show up? Or is it just that your Payout amount increased by about that amount, or ?

You can look at Activity information over a long period (up to 13 months). I'd select a few months and then search the browser page for $6 (which would find $6.03 or $60.25 or whatever) or $2 (which would find $20 however many times as well as $2.97 or other values. Perhaps that can help you find the missing item.

Or you could write to support