I just installed manjaro (gnome) using the newest iso on a Dell Latitude E7250. Installation worked and I tried the following with a swapfile and also with swap (with hibernate) from the installer (I installed it twice to be sure), as I thought the issue may be related to encryption + hibernating not working properly.
The issue actually starts with a weird first notisable issue (maybe/probably? they are unrelated): After the first update I cannot open the standard terminal anymore. I got it fixed regenerating the locale (check this forum for “gnome-terminal-wont-open-after-update/52808”). Worked but still weird on a fresh install. Anyway, the real issue is the second.
There is some weird behaviour with the display. After suspending and coming “back” on, the os is running but the display stays black - completely, without any backlight. I noticed the os running because I played a song on youtube and it played. Furthermore and I guess this is actually related, I can change screen brightness and the “pop-up window” indicates change but still, monitor brightness is not changing.
# systemctl hibernate works as intented → Laptop switches off and on reboot (+decrypting) it comes back to the old state with the windows opened as before.
# systemctl hybrid-sleep does not work → problem as described. screen off, OS running (with my magic fingers I could login and reboot from terminal without seeing 
)
# systemctl suspend-then-hybernate same problem
# systemctl suspend same problem. well this is the general one: lid closed, inactivity, … all lead to the issue.
So it seems to be related to suspend. What could I try to fix this?