Season 4 - The Season of the Empyrean Echoes with Pirate Spoil Trove (Locked) ?

[v_er]

I play season 4 and in some missions I get "Pirate Spoil Trove (Locked)" but unfortunately I don't have any keys to open it. Is it supposed to be like that? Or is this some sort of leftover from Season 3 and hasn't been removed? Weird that season 4 also features "Week of the void Brethern", which is also supposed to be for Season 3, not Season 4. I'd like some clarification.

[Schalimah]

It is because of the weekly buff.
You will get the keys by killing the blue servo skulls that spawn as well.

[v_er]

Thanks for the answer, although "the blue servo skulls" appear only in star missions (and not always) and in "Intel missions". They do not appear in crusade missions and in campaign missions, even though "Pirate Spoil Trove (Locked)" appears in all missions. It's a bit not cool that the "Pirate Spoil Trove (Locked)" is full, but you can't open them. Besides, killing (not to mention finding) "the blue servo skulls" doesn't always throw a key.

[OzBournicus I]

I have pirate spoils showing up during standard campaign play, no sign of blue skulls or keys to open them :(

[Schalimah]

The servo skulls can spawn instead of villain type enemies (skull with crown on the map).
I don't think the campaign missions have any villain spawns.

The spoil chests however can replace any chest and the campaign is littered with them.