phablet-network fails with nm system connections with '!' in its name

The factory default wlan ESSID of AVM routers is a name like: "FRITZ!Box Fon WLAN 7360" containing the brand and device name. For some time now phablet-network fails because of the !, it used to work in the past.

$ phablet-network
Network file is /etc/NetworkManager/system-connections/FRITZ!Box Fon WLAN 7360
grep: /etc/NetworkManager/system-connections/FRITZ!Box: No such file or directory
grep: Fon: No such file or directory
grep: WLAN: No such file or directory
grep: 7360: No such file or directory
grep: /etc/NetworkManager/system-connections/FRITZ!Box: No such file or directory
grep: Fon: No such file or directory
grep: WLAN: No such file or directory
grep: 7360: No such file or directory
grep: /etc/NetworkManager/system-connections/FRITZ!Box: No such file or directory
grep: Fon: No such file or directory
grep: WLAN: No such file or directory
grep: 7360: No such file or directory
Could neither find WEP nor WPA-PSK key !