Status Unknown - no message

Hi all
If my device is not available (for testing, I turned off the Client on my Smartphone), the device Status changes to "unknown". Although I configured to get a E-Mail in Server Settings, nothing happens. E-Mail notification normally works fine.
Any ideas?
Best Regards,
Peter

See following thread:

https://github.com/tananaev/traccar/issues/3324

thanks for reply
but which files do I have do edit?
...thats my first traccar install on ubuntu.

thx.

In the configuration file. Please use search before asking any questions.