Extrem slow debug launch startup

I have a strange behavior for a few days. Every debug start in an iOS project (macOS projects start up fast) that I'm working on (even in a blank new project), lasts between one minute (on a USB connection) and over two minutes (on a Wi-Fi) connection. That's so annoying! I use Xcode 11.2.1 and Xcode 11.3 Beta, the same result on both. The host system is macOS 10.15.1 on a Macbook Pro Retina 15 inch (late 2012). The app will always hang in the launch screen until it finally launches. During startup over a WiFi connection, a process called "libd-rpc-server" sends over 25 MB to the iOS device over the WiFi network, even on a completely empty sample project! I have never had that problem before! Please help!