Q: Safari search error message

I have an issue that has plagued me for years with Safari (all versions). As far as settings I have that I think affect this issue, I have google used as my search engine (under safari preferences; search etc) whenever I type something in the safari address bar.

Whenever I type in a keyword into the safari search bar, for example, today I typed in the word "badger" hoping to bring up search result of a badger, safari took me to a search result on google just as if I had gone to google and searched it there myself. And I was satisfied and went about my day.

However sometimes when I type in a keyword or a description of something I want to search, I get some kind of error page (attached and example below), and then I have to manually go to google.com to search for said keyword/ description. For instance if I typed in safari's address bar the words: keyword description (just as an example)

I would get a google search result displaying pages related to my search like I wanted half the time, and the other half the time i get a grayed out page that says this (also again, I attached a screenshot below):

The error message says: Safari can't open the page "keyword20%description" because Safari can't find the server "keyword20%description".

So why does Safari utilize google's search function half the time, and give me an error half the time? I selected the google search engine specifically for the fact that if I type something into the address bar, it will search for that phrase or sentence as if I typed it into google. But I think it is actually trying to find an address "keyword description" which will obviously turn out an error page since there is no domain attached. But what dictates when it will google search and when it will attempt to go to an address?

Is there a fix for this?

Note: I never have this issue on my iPhone

Thanks for your help guys

-Mike

P.S. In the screenshot I took I typed in "safari troubleshooting" into the address bar hoping it would pull up google search results of these forums and ironically I got the error page so I screen-shotted it.