Can't delete passwords in Firefox
I have moved to another password manager, and would like to completely remove my saved logins from my Firefox account and stop using the auto-fill, auto-suggest feature. However, no matter how many times I delete my passwords and Sync, they keep appearing in my Android Firefox app. I have cleared the app Storage and Cache, I have reinstalled it from scratch, but no matter what I do they reappear. My (also Synced) PC on which I deleted the passwords has not shown it again since I deleted them there.
I just want to completely delete all my logins in my Firefox account, permanently and across all my devices. How can I do this?