Changes did not improve the situation. Had to switch back to Synologys Motion Detection which is no alternative. @TP-Link: what has changed in recent firmware? Before this update everything was fine....

Camera settings checked / modified in Synology Surveillance Station: Transfer Protocol: TCP (UDP obviously does not transfer motion triggers) Keep-Alive-Method: NONE (has been "OPTIONS") Trigger runs...

After some days of correct operation the C200 motion detection is not able to trigger Synology Surveillance Station any more. Reboot of Synology is necessary to get it working again - for another...