User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:72.0) Gecko/20100101 Firefox/72.0

Steps to reproduce:

1. Add https://www.bing.com/ and https://www.reddit.com/ as bookmarks
2. Restart firefox
3. Enter "redd", gets auto-completed "reddit.com". ("bing" -> "bing.com" also works)
4. Press "enter" and visit "reddit.com"
5. Now enter "bing" into the address bar

Actual results:

No auto-completed result received.
If "browser.urlbar.suggest.history" sets to true and repeat the steps above, "bing.com" will be suggested as expected.
Also, suggestion like "about:conf" -> "about:config" always works.

Expected results:

"bing.com" should be auto-completed.

This should be fixed in 73 by bug 1602728. If you can still reproduce it on 73 or later, please comment here in the bug.