Firefox shows deleted bookmark in address bar as suggestion

I deleted a bookmark recently and also deleted the site from my history. That is, if I start typing the domain in the search box of either the bookmarks or history window, there are no results.

Still, as I start typing the exact same domain name in the address bar, not only does it suggest the domain name completion, but among the search results there is my deleted bookmark shown (indeed as a bookmark).

I tried:

  • manually sync with my Firefox account (if it were some sync problem),
  • delete all website data and cookies using the option in about:preferences#privacy,
  • restart Firefox using Ctrl+Shift+Q (quitting),
  • restarting my computer.

I have

  • Firefox sync turned on,
  • a number of add-ons, but none of which are dealing with bookmarks or browsing history specifically,
  • one single address bar,
  • Firefox version 86.0 on Windows 10.

Any ideas what could be wrong?

Thanks in advance!