iOS teamviewer is not connecting to host...

TeamViewer host v14, client v14, no internet connection, host and client on the same WiFi network/router, trying to connect by ip - no result! All settings done, android clients always work fine in same environment... Sometime it connects, but 95% attempts are useless... same thing on Mac or win10 hosts... Tried different routers - no result... It always worked fine, but couple of month ago it stopped working... Any ideas how to fix it?