The creation of (Q552564) is listed as happening before the creation of (Q552563), among other misordered edits
|mediawiki/core||master||+5 -1||ContribsPager: Fix merging queries in descending order|
I looked again and that is not entirely true. The contributions page is also supposed to use the revision ID when the timestamp is the same. Clearly this is not working here.
The culprit is the code that is supposed to merge in contributions to things that are not normal pages (e.g. Flow). It re-sorts all results and only uses timestamps.