User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:66.0) Gecko/20100101 Firefox/66.0
Steps to reproduce:
Start typing "https://192.168.1.2" into the URL bar
After typing "https://192.", it autocompletes "0.0.0" after my cursor, unhighlighted, so that further typing leaves the "0.0.0" after what I type.
If I shift-right-arrow to highlight the "0.0.0" and continue typing, when the URL bar shows "https://192.168" and then I press ".", it autocompletes to "https://18.104.22.168" and leaves my cursor immediately before the "168".
There are variations of this, depending on how much of the IP address I've typed.
Any autocompletions should happen after the cursor and be highlighted so that further typing will overwrite the autocompletion.