Tried running various Linux distributions on the XPS: elementary OS, Kali Linux and now Solus OS - all of them shipped with NetworkManager. In my current housing situation we have a hidden wifi, and I have no chance to change that. Interestingly, when I tried to connect to the hidden wifi using the nm-applet, the connection always closed and I got no meaningful errors.
Additionally, I have a Lenovo Thinkpad Yoga S1 running Arch Linux and using netctl for wifi, which had no issue whatsoever to connect to the hidden wifi; I did have to write the config file on my own though, but it only differed from a regular wpa connection by one line, namely Hidden=yes.
What finally worked for the XPS was a set of commands to address NetworkManager's command line interface:
nmcli c add type wifi con-name <connect name> ifname <network device> ssid <wifi ssid>
nmcli con modify <connect name> wifi-sec.key-mgmt wpa-psk
nmcli con modify <connect name> wifi-sec.psk <password>
nmcli con up <connect name>where <connect name> is your personal choice how the connection shoud be called, <network device> is usually something like wlan0 or wlp2s0 (find that via ip a in your console), and <wifi ssid> is the name of the hidden wifi.
What's surprising is, is that the wifi is not marked as hidden in the configuration created this way, although it doesn't show up in any normal search for wifis and I needed the abovementioned Hidden=yes paramenter for netctl to work.
Interesintgly, as far as I remember, I tried those commands as well on elementary OS and on Kali Linux, but they didn't seem to work there; whereas on Solus OS they did. But I'm not entirely sure whether I used the exact same commands (with adjusted network device), and whether the used version of NetworkManager was the same.