Access to my Swiss based VPN does not work correctly when travelling to France.

Recently I set up a Swiss based VPN. The objective is having access to my home computer (iMac, OS 10.12.2) and eventually other devices via internet. The access to my home computer from other WiFi networks located in Switzerland works fine (file sharing is ON). However, connecting from a WiFi network in France is only working partially. Although there is a connection to the VPN in Switzerland, my home computer cannot be found within the VPN. For instance, in the finder window, go, connect to server: the browse button does not see my home computer, nor other devices connected to the VPN. Actually, I tried a connection to server with: afp://192.168... and smb://192.168... Both are working fine by using a Swiss based internet connection but not a France based one. What can be done?