For Madhu and others experiencing this issue who do not have mod_groupformation installed, I would suggest some other installed plugin is likely not following the current JS guidelines, and triggering a similar bug. I did also test mod_grouptool, which seemed fine and did not cause the same issue. If you are able to identify the culprit(s), the best course of action would be to contact the relevant plugin maintainer, so they are hopefully able to address the issue and publish a compatible version.
Regarding the search.php URLs ending in #linkusers, #linkcourses etc, those are correct on the relevant admin section, and have just been updated in that way to allow refreshing/navigating back in your browser to that admin page to retain the correct visible section on the page, rather than defaulting back to the base "site administration" tab.
I hope that information is helpful, and you're able to find any remaining sources of the issue soon!