Oxygen Masks won't deliver to dock

[Chaddric]

Need some help here,

Oxygen Masks won't deliver to oxygen mask docks. I have 2 docks, 5 masks, priority on the docks is set to 9, navigation to the dock is good, so I do not know why the masks won't deliver. I know its not to many tasks because lower priority tasks are getting done. 

[DarkMaster13]

What are the priorities on your dupes?  Suit deliveries are weird since they don't seem to fall into most of the normal categories.  Also check your door rules and maybe get rid of that atmosuit checkpoint until you actually have atmosuits.

[Jorge Junior]

-clearance
-vacanacy

When you click on the checkpoints, you will select the 2 above in the bottom right, try them.;
Make 2 layers, one with oxygen masks and the other with atmosuits.

[Gurgel]

Usually this is a priority problem. Do they get delivered when you place the docks on yellow alert?

If not, the cause is likely the two checkpoints in series somehow or the doors, as commented on above. 

If the yellow alert does get the masks delivered, then it is a priority problem and you have too many things on priority 9 or other stuff set higher in their personal priorities for the dupes that could deliver the masks. You can check actual task queues and actual combined priority on each dupe in their personal task list.

The personal task priorities are actually higher in significance than the ones on the docks/objects/machinery. Example:

Here you can see that Camille has 9 prio from the plant, but 40 from her own farming preference and 0.5 all farming gets. Yellow alert overrides that, which can be good for testing whether there is any dupe that can do something. Just as illustration, the same with the plant set to yellow alert ("!!"):

You can see that personal preference gets dropped for Yellow Alert, i.e. emergency tasks. If there is a dupe that can do the task they will do it. If the task is impossible to do you will find that easily with this as well. 

Now, if the task can be done but does not get done, pause the game and look at all dupes until you find that task in their Current Errant list. Then look at what priority overall it has and fix that if needed. It helps having one dupe that specifically has a high prio for such tasks, but you can also balance things out overall.