APWeb not working with Tailscale IPs (works with Zerotier, though), maybe broken mavlink-router?

Hi all,

i'm experimenting with APweb together with IP-VPN-tunneling platforms, which basically are two: tailscale and zerotier. Generally i prefer the first, as it seems to have better video stream performance. However, going with APWeb through tailscale (which basically consist of putting tailscale assigned IP into web browser) gives APWeb pages BUT without any communication with the FC ! (blank fields, etc) and "broken" video stream server page (empty network interfaces list).
However, just going with zerotier IP, everything same, it works ok, i can see comunication with FC, stream server page works ok. I'm not very deep into project but i think it's an issue with mavlink router, maybe?
I'm using APWeb included in apsync-Raspian-20191123030859.img image, since i tried to compile latest from this git, but it gives me an error

Reproduce the APWeb behavior using the Tailscale IP and compare it with the working Zerotier setup. Investigate the APWeb-to-flight-controller communication and stream server network-interface handling; done means populated FC fields, a non-empty interface list, and a working video stream over Tailscale.

Written by the indexing model from the issue text.