Question greet trigger in dark room

Hmmm the mob has infra on, the room is dark....this trigger only fires if the char who enters the room holds a torch.

Is that suppose to be like that ?

Name: 'kobold miner hums', VNum: [12610], RNum: [ 1618]
Trigger Intended Assignment: Mobiles
Trigger Type: Greet , Numeric Arg: 100, Arg list: None
Commands:
wait 1 s
%echo% The kobold miner hums.
wait 15 s

Start with HELP TRIGGER-TYPES
Then go to HELP TRIGEDIT-MOB-GREET
and then HELP TRIGEDIT-MOB-GREET-ALL

Tnx greet all worked. But still a mob with infra should be able to see

Sounds like the mob can't see the character.
You can switch into the mob to confirm this.

Other things that will prevent a greet trigger are:
The mob is not awake, mob is fighting, mob is charmed.

If that is all fine, then it comes down to the CAN_SEE macro, this is the only difference between greet and greet-all.
Simplified:
o char invis level is below the mob (mortals should be invis 0)
o mob is not blind
o there is a light in the room OR mob has infravision (stat the mob to confirm)
o character isn't invisible OR mob has detect invis,
o char is not hidden OR mob has sense life..