Amazon Kindle (the cheap one)
Orbot v15.1.2 (F-Droid)
Silk v47.1.80.<lots of other numbers> (builtin)
Chrome v46.0.2490.76 (builtin)
Using Orbot's VPN mode several apps intermittently report DNS failure, but only with some sites. Sometimes repeatedly refreshing will work, but not always.
Sometimes the failure is instant, sometimes it takes long enough for a timeout.
There are other failures (frequently 500 range), but this one annoyed me enough today to report it.
Orweb & Orfox (both current version) work more often than Silk, but less often than Chrome.