Patch chains don't show previous and next patch links anymore

Push a set of three dependent patches (A-B-C) to gerrit, approve them and then let the CI work them over. I have multiple cases where the patchset was split up once the CI came back with an error.

When looking at B the UI did not present the required links to the previous or next patch in the chain anymore. Note that the links did exist before the first staging.

Here is one example:

https://codereview.qt-project.org/#/c/87914/ (A)
https://codereview.qt-project.org/#/c/87915/ (B)
https://codereview.qt-project.org/#/c/87916/ (C)