Contextual Filter Request That Includes Space Character Returning No Results

Any request to a contextual filtered view that contains a space character is returning zero results. Any suggestions?

Details as follows.

I have created a "webform results" based view as described in this tutorial:

https://knackforge.com/blog/sivaji/displaying-webform-submission-data-dr...

The view includes a contextual filter that works as expected when the filter parameter is a single word like so:
/myview/singleword

However, when the filter parameter is effectively two words:
/myview/two words

I don't get results

I have experimented with maybe a dozen permutations. For example adding a dash:
/myview/two-words

Enabling:
"Transform spaces to dashes in URL"

Even leaving the space out.
/myview/twowords

However, nothing I tried returned a result when there was a space character in the parameter..

I'm not sure if it's something to do with requesting webform data instead of a node or, a general issue.

Any suggestions?

Thanks.

Cheers

Brett Sh