I've generated a return label but when I go to send it, I get the "oppsie" message. Can't even download the label and send it myself nor can I find a place to try and send it in the app.
Also, I am not finding a way to see buyer history in the app?
This is a recent bug with return labels. I encountered it myself a few days ago. Contacted Chat, and they are aware of the issue. Lots of other posts about this, the past 2 weeks.
You can create a return label (pay on use, just like on Etsy) on PirateShip. You may need to use their chat to enable it the first time.
As for the app - still lots of things missing. Use the desktop site on mobile.
So two weeks and no fix? Awesome.