Solved: In some very rare circumstances fixtures react on glitches on the DMX line and show an unexpected movement on Pan/Tilt.
UPDATE PROCESS
Main, Effect and Pan-Tilt driver can be updated in sequence (D2Prog Version 38 or higher).
Or in one single file (D3Prog, Version 38 or higher).
When importing the hex files into a Dprog (version 38 or higher) please make sure that you choose the file type Intel standard file (Hex- file) before uploading the files to the programmer.
Fixtures can be updated daisy chain via RS485/DMX. Please make sure that no other DMX receivers or consoles are active on the line.