Language temporarly resets to system language when opening external app

Steps to reproduce

1. Set language inside the app to something different (in my case: system language is german, app language is english)
2. Click on a post linking to something (e. g. YouTube)
3. Select external app in the dialog and open with it (NewPipe for YouTube)
4. Exit external app, return to RedReader (Press back key)
5. Scroll down to load new content

Note: This only seem to happen when you get asked for an app when clicking on it, not when it opens the internal browser first and then opening the app from there.

Expected behaviour

Language doesn't change.

Actual behaviour

Language switches for new text. But most actions seems to fix it. (e. g. opening other subreddit, opening comments... Going back to main menu and clicking on "reload" doesn't and makes everything german/system language)

Info

Samsung Galaxy S3 Mini (GT-I8200N)
Android 4.2.2 (default ROM from Samsung)
RedReader 1.9.8.5 (from F-Droid)

Reproduce the language reset by opening an external app from a linked post, returning to RedReader, and loading more content. Start by tracing Android external-app handling and the app lifecycle around returning from that intent. Done means the selected in-app language remains active after returning and loading new content, including the direct external-app flow described in the issue.