After linking out to another app, strange redirects start to happen

The Codex Search application now correctly links out to full-record displays in other apps: Inventory for local records, eHoldings for KB records. But as discussed in UISE-50, after having followed a link out to another app, strange redirects start to happen. Odder still, the behaviour varies in predictable ways between the two apps.

1. Start Stripes from fresh
2. Go to the Codex Search app
3. Set the query-index to Title (which BTW it should start as: UISE-57)
4. Enter the search-term "a"

From here, you have a choice:

A5. Click the local record "14 cows for America". It displays in the Inventory app.
A6. Hit the Back button. The URL visibly changes to the Codex-app URL, then immediately changes back to the Inventory record.

Alternatively.

B5. Click the KB record "A**-hole-ol-ogy (Assholeology)". It displays in the eHoldings app.
B6. Hit the Back button. You are correctly returned to the Codex search app.
B7. Type "i" in the query box. The page immediately jumps to the eHoldings app's page for "A**-hole-ol-ogy (Assholeology)".

So: it's super weird that this happens at all. But even weirder that it happens differently in the two apps – and that the difference between them is reliable.