strange behaviour respect to gnirehtet

[gilcu3]

I'm on a LG Nexus 5 AOSP ROM Android 7.1

I was testing methods for reverse usb tethering and found the following:
With gnirehtet, most apps (except google apps) work without having to turn data nor wifi on. For example Whatsapp and Telegram work without issues.

With SimpleRT, I get the conection, I can ping machines in my local network, but some apps work perfectly (dont need wifi nor data) and some others don't (need wifi or data). For example, Whatsapp works and Telegram doesn't.
The question is: why is that if both use VPN connections? Is it fixable?

A different minor issue with SimpleRT, sometimes after disconnecting usb the VPN service stays running, and must be closed manually.

[Sur3]

Excerpt from the minor USB-issue you mention, this is a duplicate, see #3

Greetz
Sur3

[gilcu3]

hmm, could you explain why this is a duplicate? I mean, what does gnirehtet do to make a difference with respect to Telegram app?