We are publishing a feature service to Portal (10.7.1) from Pro (2.4) for use with collector, and we'd like to enable feature attachments so that a photo can be taken in the field. We have enabled attachments in the enterprise geodatabase, and they are working in Pro (we can add an attachment just fine via pro). When we publish to a feature service, however, the feature service is missing the button "Enable attachments".
It's a little frustrating as all of the ESRI help just says "click the Enable attachments button" but doesn't say what to do if there isn't an enable attachments button.
What ESRI wants me to do:

What I see:

Any ideas?
Thank you!