Certain links in references are not working in the app (but do work in the m.web and iOS app)

First reported in OTRS: https://ticket.wikimedia.org/otrs/index.pl?Action=AgentTicketZoom;TicketID=10446157

Steps to reproduce

1. Go to the article in the app Jessica Hart (model)
2. Tap to view citation reference number [8].
3. Tap on the link "Out with the pout" shown in that reference.

Expected

The link opens in the device browser.

Actual

The reference pane closes.

Detected on

Pixel (Android 8.0.0) on Wikipedia v2.6.206-alpha-2017-11-17