Tobias:
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You forgot to include an SSID after your callsign for the APRS-IS server login.
IGLOGIN KK7BCO 19620
should be.
IGLOGIN-10 KK7BCO 19620
(or whatever SSID you want to use.) The list of SSIDs is found on page 58 of the Direwolf user guide.
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73 de DV7GDL