Sorry/Glad someone else is experiencing this issue.
The navigateUrl function is now (recent) failing for my custom dnn module.
I do not see what has changed.
I do see that if url is in form

https://myDnnDomain.com/childPortalName/Home/tabid/10667/Default.aspx

instead of

https://myDnnDomain.com/Home/tabid/10667/Default.aspx

the navigateUrl will return the domain as needed.

So navigateUrl(tabId) will return "/Home/tabid/10667/Default.aspx" if the url does not have the portal name/child name

This is a large problem.

I have a custom module that sends email that includes a link back to a page in the site. To form the link, I used the navigateurl function. This worked for five years or so without issue. Just recently I have reported failures in that if the page that posts the request has a url in the form of

https://myDnnDomain.com/Home/tabid/10667/Default.aspx

navigateUrl will return /Home/tabid/10667/Default.aspx instead of the entire url.

navigateUrl will only return the entire url if the page that posts th request has a url in the form of

https://myDnnDomain.com/childPortalName/Home/tabid/10667/Default.aspx


I do not know what changed as I did not recently change friendly url settings etc. The mother (500+ child portals) has been running with little change to host settings for beyond the 5 years that this module has been in place.

I have coded around the issue by checking the url for the existance of the domain and inserting if not.