search for strings with embedded spaces

[ChrisGreaves]

This is going to be difficult because I am asking about “embedded spaces in search”, which, to the best of my search ability, does not appear in Eileen's Lounge, but once I Submit, the topic should exist.

Here in Eileen’s Lounge
(1) I do a simple generic search for “embed*” and get 789 matches.
Once I Submit this post that value should increase. (later: it did. To 790 matches)
(2) I do a simple generic search for “space*” and get 4,136 matches
(3) I do a compound generic search for “embed* space*” but without the quotes and get 11 matches.
So far this all makes sense. I am not counting out each match, but the compound search count (Intersection) is less than both simple searches. I inspect one match and see that the string “embedded space” without the quotes exists within that topic.
(4) Thus emboldened I do a compound search for “embedded space” but without the quotes and get 9 matches.
OK (hesitantly)
(5) Then I do a compound search for “embedded space” but this time WITH the quotes and get 9 matches.

At least one reported match has embedded and space peppered throughout the posts in the topic, but in Vivaldi browser, Edit+Find turns up no instances of “embedded space” with or without the quotes
So I figure that I don’t understand how to do a search for a string of characters that contains a space, as in “embedded space”
And now I am heading into a loop, to wit:-

How do I search this site for the two strings “search” and “embedded space” to find out how to search for topics that tell me how to search for strings with embedded spaces.
My brain is hurting.

Footnote 1: I have been essaying with this off and on for most of the day on four other phpBB sites, using different strings, of course, but with no success.
Footnote 2:Be warned: after this my next search will be the equivalent of a search for all topics that match “embedded space” as a string, but not “embedded” as a string by itself.

Thanks
Chris