iOS 11.4.1; iPad Pro 10.5; latest production version of Bible app.
I was on a flight yesterday, no wireless connection on my iPad. I was in Romans 2-4 in ESV (downloaded). When I tried to touch a word to do a BDAG lookup (my prioritized resource, which works online, and which previously worked offline), I almost always was getting the error about not having downloaded a default iOS dictionary. But on at least one word I did get the BDAG information. (I later confirmed that I wasn't picking words that had no corresponding lemma in the RI).
In the past, I've found that the app acts differently when wireless is enabled but not connected to a network vs. when wireless is disabled altogether. So I disabled wireless altogether. At that point, it did a bit better doing the lookups. But after finding BDAG for a word the first time, it then started going to ISBE for all the words. (I later confirmed that the words had BDAG entries.)
Again, I later went online and got the behavior I expected, which I believe should have been the behavior I experienced when disconnected / offline.
Thanks,
Donnie