https://archive.softwareheritage.org/static/lib/core.js (and various friends, just open the javascript console after visiting the search page) returns 404. Maybe cryptojs is not installed on tate, or the symlinks from the webapp are broken, or not followable.

That means the webapp is unable to compute checksums, breaking search completely.

What's weird is that it seems to behave erratically, either returning all files as known, or none of them as known.
This might deserve separate debugging of why it is happening.