i do not want to start new topic yet.
I have configured ZeroTier on RUT2XX 00.1.11.2. On router side everything works for two days (route uptime is 6 days).
After 2 days of proper working suddenly connection via ZeroTier is unavailable.
Router shows proper Address but ZeroTier interface shows that device is offline since 4 days.
Device has not been rebooted and I noticed one communication gap for 10 min (single http request did not response).