Bookmarks being carried over despite account deletion

Hello, I have been facing an issue that I want to completely delete all of the bookmarks associated with Mozilla Firefox. Manually deleting them works temporarily, however, they return to the bookmarks bar upon reinstalling Firefox and logging on to my account I have already tried deleting my Mozilla account completely and used RevoUninstaller to delete all and any Firefox files from my system (done this to one of my computers). Still, the bookmarks return when I reinstall Firefox and log in to my account. I have also tried not syncing with other browsers, and the bookmarks still return when I log in to the Firefox account. This persistence is annoying, because I really would like my bookmarks data from Firefox to be completely wiped out, but it seems that they are returning even upon account deletion (I created a new account using the same old e-mail). Could someone please help me with this issue?