Zerotier Android - some internet traffic gets disrupter when Zerotier network is active

[giobatta]

When a Zerotier network is active, some internet traffic is disrupted.
Zerotier is configured NOT to send all traffic to remote network so the option "Route all traffic through Zerotier" is unticked.
Nevertherless application like 3CX do not work when Zerotier VPN is UP.