I am using domain and domain menus in a site and I have one view page listing with multiple displays on a same path, and all the displays have particular domain, in my site, I am displaying expanded parent link on the specific page.
for example:
Parent Link: Car
Child Links: Toyota (View page link), Mazda (Normal menu link), Hyundai (Normal menu link)
Proposed Behaviour: When I go to any child links the parent menu should be appear expanded.
Actual Behaviour: When I go to view page link the parent menu isn't showing up expanded, but when I go to normal menu links it works fine.
I dumped the menu in preprocess_menu on actual pages and screenshots are attached.
Closed: cannot reproduce
3.5
Code
I'm not totally clear on how to reproduce this, as it's unclear how you're displaying your menu and with what settings.
But I don't think this is a Domain Menus issue.
I might be able to help if you provide more information about how your menu is setup and displayed.