Adding to what sense-design and mlncn already reported, I found out that the reason getActiveTrailLink() returns such results for View-generated links is probably because /Drupal/Core/Menu/MenuTreeStorage's loadByRoute() function searches for route_param_key, which View-generated links have not. I tried creating a link to the View page manually via UI and then the route_param_key was properly populated and the active trail worked as expected.
So I searched if there is a way to populate that table field while creating it via Views, or if I can alter loadByRoute() query, and found out that there is a related core issue: [regression] missing menu active trail since Drupal 9.5.9 🐛 [regression] missing menu active trail in Drupal 9.5.9 Needs work . I applied the latest patch (#103 as of now) 🐛 [regression] missing menu active trail in Drupal 9.5.9 Needs work to Drupal 10.4.4 and the active trail worked for Views-generated links.
However, in case someone wants to avoid patching Drupal core, I did some work on current module's getActiveTrailLink(). I added an if-clause to handle the case of Views-generated links and make it return a proper result to add active trail. I attach the patch and leave the related MR is here: https://git.drupalcode.org/project/menu_trail_by_path/-/merge_requests/18.
vensires → credited gkffzs → .