Orbot's VPN is not followed by apps (Android 8.1)

I installed orbot from https://github.com/n8fr8/orbot/releases selecting universal release because of https://trac.torproject.org/projects/tor/ticket/26126 . Problem is that the VPN that orbot creates is not used by any app.

I use Resurrection Remix (RR-O-v6.0.0-20180512-klte-Official) based on android 8.1.

Also I installed AFWALL+ allowing only VPN access to apps (not including orbot) and the apps stop having access to internet. For example Firefox stated 'Unable to connect'. Without AFWALL+ filtering, when I visit check.torproject.org it shows my public IP address.

Trac:
Username: pant