You can try to use "hidehud" cvar on console and check if there is any value that hides the score HUD
Code:
hidehud
default: 0
flags: "cheat", "cl"
bitmask: 1=weapon selection, 2=flashlight, 4=all, 8=health, 16=player dead, 32=needssuit, 64=misc, 128=chat, 256=crosshair, 512=vehicle crosshair, 1024=in vehicle
Then if you find one, try to apply it to the client through a plugin.