I am designing a report for a municipality that shows different measures that municipality should take. The whole report has more content so I have set up one master page that has the page numbers and a heading at the very top (master page A). Dependent on that I have set up a master page B for the pages detailing these measures (master page B, based on master page A). The measures use a repeating layout with a few elements at the top of the page (a little icon, a number and a title) and below that more content that varies from measure to measure. Some measures use more than one page in which case only the first page uses master page B and subsequent pages use master page A. The whole document is set up as a two-page-spread (it will become a printed report in the end), so it has left and right pages (and some elements are mirrored, for example page numbers are always in the outer corner).
I have locked the icon, number, and title elements on the master page and enabled selection of locked elements in my preferences so size and position is retained but I can edit the content, to make sure that these elements stay attached to the master page, because we might decide to change the layout at a later date. (This was part of my problem, and was solved after I discovered this thread: How to lock the position and size of a text-frame in InDesign CS6?)
We are still working on the actual content and producing maps and illustrations and other things, so content moves around and pages get added and deleted.
My problem is as follows: When I add a single page, all subsequent pages change their "orientation" (left pages become right pages, and right pages become left pages) because I want to preserve two-page-spreads all the way through. Apparently InDesign does not recognize that the master page elements (icon, number and text) are meant to be the same on left and right pages, and thus it re-creates these master page elements on all subsequent B pages and leaves my modified version (with custom icon, number, and text) below them.
This is what it looks like after inserting a single page right before the page shown in the picture. You can see that the original content has disappeared behind the newly created master page elements.
I would like to preserve their association with a master page so I can still easily change the layout later. Is there any way to create a master page that is the same for left and right pages, even though their parent master page is not? (e.g. I have page numbers and other elements different on left and right pages, but the elements that are specific for the pages with the measures stay the same, so it doesn't mess up the document when pages go from left to right or vice versa) Alternatively is there a way to associate master page elements on left and right pages with each other, so when a page goes from left to right or vice versa, InDesign recognizes that the master page elements should stay the same?
I already tried changing master page B to a single page master layout, but that did not work - it only preserved the elements from the left page of master page A.
I hope this explanation is understandable, and I thank you for any advice in advance!