I would like to check the DECT log from the 300Wx unit when this is happening.
Activate logging by doing this:*
Longpress on the Hold button (Lower left corner).
Longpress on the Line mode button (Lower right corner).
Then you enter a service menu.
Put in an SD-card to get the logfile.
Go to service logging and chose LOG ALL.
Make the call or try to register to a dect base depending on the problem.
Wait a while for the logging to be saved.
Take the SD-card out and put it in a PC.
Copy the log and email the logs to me.