Thanks for sharing your report with us, @Christoph_Eichenseer!
To start, may I kindly ask that you please provide a brief description of your current setup using this link as a guide.
Make sure to describe your network configuration/topology, including any networking hardware currently in use, so we can have a clear understanding of how your devices are communicating.
May I also ask that you please verify the following:
- Since noticing this behavior have you tried rebooting the tablet, Core machine, and networking hardware?
- What version of Android is the device running?
- What version of Android is the phone that does work running? What kind of device is it?
- Do you have any active antivirus or firewall on the Core machine? Does disabling them yield positive results?
Regards,
Dylan