These are the current issues with group finder that we are experiencing (this is strictly for dungeons, and not BGs).
1) If your queue pops as you are in a load screen, then you have to be vigilant to look in notifications after the load screen as there is no visual queue on screen requesting the ready check.
2) If you get no visual queue (because of combat or load screen like above) then the notifications shows your timer at 00s as default, and there is a 50% chance that you won't be able to accept the ready check at all... and it stays that way indefinitely.
3) If you have to requeue because of missing a ready check (usually because of reasons above) then queuing for a specific dungeon can lead to a second (unselected) dungeon also being "checked" at the point of hitting activation on the queue (my wife and I queued for Vet Scalecaller, and got pulled into Vet Fungal Grotto II two days ago...)
4) There is an intermittent error when auto-porting into the dungeon doesn't pull in one of the people, and to that person they don't look like they are in a group at all, and so never port in (unless you whisper them and even then they cannot port in as they don't appear to be in a group with anyone). This error is unconfirmed to the cause - but suspected that it is directly linked to the no.2 listed issue).
Anyone else experiencing these issues? I would put it in bug reports - but I wont' to clarify first that others are seeing it.