Dropping of the Server connection can happen when the WiFi is unreliable. Here are two things you can try to see if you can mitigate this:
1. Change the polling frequency that Designer uses when updating inspectors. By default, this is 10 Hz and if the WiFi connection is slow this can saturate traffic. Search for the file Designer.ini which is found in Bin/Assets. You'll find an entry like:
If you don't see these lines, just append them to the end of the INI file. Change the 10 to something lower, like 3 Hz. You'll have:
2. The Server has its own INI file. You can access it from the Server window under the Help --> Open INI File. You'll find a section similar to:
This specifies the time out values for the different tuning interfaces. Try changing TCPTimeout to 4000.