I'm not SE...buuuut

When You queue with other people and the wait 'goes fast', how fast do you mean?

Also, what roles are the other people queueing as? (because if it's tank and/or healer....you are riding their 'needed' queue more than there being a glitch...tanks/healers have much shorter queues than DD's b/c there are less of them)

And when you queued with friends, exactly how many did you queue with...if you queued with 3 others, and did a 4-man instance, obviously that'd = and instant queue. If you picked up 2 ppl for a 4 man, well that'd mean that at least one of your friends queued as either tank/healer which also has the effect of speeding your queue (see point above)

What exact content are you queuing for. ST/Frontlines/Duty Roulettes/4-man dungeons/Primals ....this all matters too