Hmmm..Thanks for confirming that at least.
Have just tried again now - (GC2Y1XW) - showing 3 Trackables. Tap on the Trackables field and the background greys to show a tap event, but does not navigate to inventory page. Related, yet unrelated, the Favorites button works fine.
For the record, the device is an 8s running iOS11.2.5.
Certainly no biggy, but a niggle.
Any other possible causes?