This seems to be a very basic question that I can't find an answer to, I would like to set a fixed map extent in Pro but when I "use a custom extent" in Map Properties the map does not fix to the extent I select.
Potentially check out Map frame constraints—Layouts | Documentation using the layout map frame constraints options, I believe this contains the functionality you are looking for if you haven't looked there already. Is there a requirement to set it only within the map? I hope this helps answer your question.
