Evoq Basic 9.1.1

Using the Settings > ... > HTML Editor Manager screen, I configured the CKEditor ("advanced editor") so that users can apply a text style: CKEditor wraps the selected text with a span.whateverClassIdefine

Saving and returning to the advanced editor results in the span missing, being filtered out by CKEditor's ACF (advanced content filter) ... but I want the span to be retained (not filtered)

Back in HTML Editor Manager, I set AllowedContent to:

default

I set ExtraAllowedContent to:

span

also tried variation with quotes:

'span'

Results: the ACF still filters spans.

* reaching for hair to start pulling then taking a deep breath *

When I try to set AllowedContent to blank/nothing, it's automatically set to:

true

... from CK's docs this means that ACF shouldn't filter anything, yet spans are still filtered.

So, has anyone used the HTML Editor Manager and successfully allowed arbitrary html elements to not be filtered by CK's ACF?