While using InDesign v17 I've encountered a bug where some small rectangular vector objects will get larger when a page is duplicated using the "Create Alternate Layout" feature in the "Pages" tab. This has also occurred when a page or layout is dragged and dropped to the "Create New Page" icon to create a duplicate in the "Pages" tab. Design elements should not change when a layout is duplicated, and this did not happen in previous versions.

This first appeared in an .idml file that was created in 2019, and carries over to new files based on that .idml. It does not seem to occur with .idml files made in 2020 or 2021