I had the problem that I was not able to find any gateway via browser.
The problem was caused by a missing library:
12:13:55:933 error loading plugin: Cannot load library /usr/share/deCONZ/plugins/libde_rest_plugin.so: (libcrypt.so.1: cannot open shared object file: No such file or directory)
The solution is to install the package libxcrypt-compat from AUR. This package contains the missing library and now the Phoscon App can find the gateway.
Hope this helps somebody…I was almost about to give up (;