Some returns not automatically refunding

This is probably something I missed awhile ago, so please forgive my ignorance. I’ve been selling on Amazon for a decade. I of course have had many returns over those years, but for a long time now (I finally just stopped thinking about it) I didn’t even bother looking at return status because Amazon automatically refunded any returns sent to me. It was annoying because occasionally those returns never actually to me but outside those instances I pretty much ignored the return process after getting the item because Amazon seemed to take care of everything else.

Flash forward to a couple days ago when I got my first ever A to Z case. Customer says they returned something to me in early June but never got a refund. I went in and looked at my returns and indeed saw it sitting there and not refunded. I also noticed 2 others over the last 6 months that were never refunded. Whoops! Took care of them but realized I obviously need to keep a constant eye on the returns. Amazon is still refunding nearly all of them automatically but some they do not.

Is there any way to determine which returns Amazon is going to automatically refund, or do I just need to keep constant track on my own?