Hi @tiblop, thank you for your report. If I can summarise in preparation for reporting to the developers (please correct me where necessary).
You are using the Tobii Core SDK which is reporting erroneous gaze data locations on your secondary monitor which is fixed when the computer is started with the secondary monitor connected.
I assume the DPI setting has no effect on this behaviour? Also, if you connect the monitor *after* startup, are the windows display settings the same? (ie same position, etc)
Thank you for the additional detail, however one should bear in the mind that the current Core SDK does not as a rule support multiple monitor displays, however I will endeavour to provide you feedback as appropriate.