In https://chromiumos-build-annotator.googleplex.com/build_annotations/builds_list/master-paladin/, if you click the "Update List" button thinking it will refresh the build list, it does the exact opposite: it adds latest_build_id= to the URL so that you do *not* see an updated build list.
And then if you F5/refresh after that, the latest_build_id in the URL means that again, you won't see any new builds.
I spent most of yesterday thinking there were no new builds to investigate. Which seemed a little weird, but I don't normally watch the tree to know how many to expect.
Suggest adding a "refresh to latest build" button which will clear the latest_build_id from the URL.