When you scroll to the bottom and look at the box with status reports from integrations, there's a Details link. My app reports a check called "Timeline protection" via Checks API.
This details link is supposed to take the user to the Checks tab in the PR (https://github.com/tox-dev/tox/pull/1272/checks?check_run_id=159224582).
Sometimes it works properly, but often it links to the app installation page (https://github.com/apps/psf-chronographer) which is weird.
I'm unable to reproduce the problem you're describing using the example link you provided.
Are you still experiencing this issue?
I'm having the same issue. I have a GitHub App that creates check runs. The check runs have a `output` field and there I supply some additional information. I do _not_ supply the checkrun with a `details_url`, as I want the output to be visible in GitHub.
Sometimes all check runs in my check suite will have a details link directing to the home-page of the GitHub App (https://github.com/bobvanderlinden/check-reporter). Other times a link to the actual check run details page is used: https://github.com/owner/repo/pull/1234/checks?check_run_id=163078825. This last case is what I always intend to happen.
What is also interesting is that the checks and their output/details do always show up correctly in the Checks tab of a PR.