That seems very strange. Normally, when you submit a a URL, it opens in the same tab, or in a new tab in the active Firefox window. (But I run Windows, so there are some differences.)

Thanks for writing. I know -- it is very strange. I have turned off all suggestions, and I still can't type a complete web address in -- a suggestions box opens at the bottom of the page and I have to manually close it before I can complete the address. I am starting to think that I may just have to switch to Safari. This is irritating me.

The box about choosing a display is not part of the address bar drop-down, it is a separate dialog? Any chance you could screenshot it?

As you probably have noticed, search engine suggestions are not requested until you type the second letter into the address bar. If you start typing very slowly, does the appearance of the dialog seem to be associated with search engine suggestions? I guess you already tried disabling them on the Preferences page:

Thanks you. I will try to send a screenshot the next time this happens.

I just restarted Firefox to see if perhaps that would fix it. I may try restarting the computer.

I did turn off search suggestions. As far as I can tell, I have turned off every kind of suggestion I can -- even helpful ones like filling in a bookmark, etc.