Team Viewer freezes while showing connection window

When I connect from my iMac Pro to my MacMini within the same newtork, the connection starts, but after a few seconds a batch appears telling me: "Einsetzen von Server-Mac ...." and below "Verbinden ...". and the connection freezes while the colored ball turns.

in English: "Inserting from Server-Mac ..." / "Connecting"

After a while the connection work and after seconds the problem reappears.

TeamViewer outoruns on the MacMini how is configured as my network server.

Any idea what to do