Huh. Set a profile picture in the Nextcloud account I've been using for years, also using it in my phone's Nextcloud app. Apparently this updated a contact in my phone's contacts (a Google contact, I usually create contacts for the Nextcloud account, but the system sometimes creates contacts for accounts) with the picture‽ This led to K9 Mail also setting the picture for my mail account which is mail@mydomain despite the contact's mail address being nextcloud@mydomain (forwarding to the mail@ address). What is going on?

Changing the contact from Google to Nextcloud had it lose the image and K9S as well, but this is somehow scary. Setting a pfp in one app should be contained unless explicitly intended.