TY. I followed all 3 methods, but in each case there were no subscriptions listed. As such it seemed like the subscription is coming from somewhere else. I tried my three email accounts just to be sure, but that was the same result. Should I contact my bank to deny any and all future charges from einkpads? I hope that would be a last resort.

@Jason Smith found the folder in my windows pc, and I see carousel.json but no .png file. Somehow I don't think the software is generating one and/or overwriting. I've tried via usb, Wi-Fi, and the direct connect (which I read doesn't support carousel anyway). I'll be disabling the feature for now, which is unfortunate since that is a feature that really appeals to me.