Swiping away doesn't always disconnect from tor

Summary

Sometimes when closing the app by swiping it away from the recent items screen, reopening jumps straight back to the "HomeFragment" (default browser screen) and browsing works normally, suggesting that the tor process stays running.

Steps to reproduce:

1. Bootstrap
2. Open https://check.torproject.org/ and note the displayed IP
3. Background app for roughly 5 seconds
4. Open Recent Items screen and swipe away the app
5. Reopen the app and notice that bootstrap is skipped
6. Reopen https://check.torproject.org/ and notice the IP is the same as before

What is the current bug behavior?

Bootstrap can be skipped

What is the expected behavior?

Bootstrap should not be skipped

Environment

Which operating system are you using? For example: Debian GNU/Linux 10.1, Windows 10, Ubuntu Xenial, FreeBSD 12.2, etc. Which installation method did you use? Distribution package (apt, pkg, homebrew), from source tarball, from Git, etc.

Relevant logs and/or screenshots

Swiping_away_doesn_t_always_disconnect_from_tor