No no, I probably did not express myself clearly. I thought that you meant that a static IP was needed for using Radicale with DecSync CC.
I only talked about Radicale on the desktop in the posting above. When it comes to Android, then following your explanation in this very thread, I have also installed DecSync CC on several Android devices and use Syncthing to transfer the DecSync folder, which itself is linked to Radicale on the desktops with the plugin.
All in all, my setup right now is probably very similar to yours.