[1.1] Cannot merge two stacks of items from two distinct stockpiles

[Belp]

The full version number is 1.1.2561.

Circumstances:
I have two stacks of identical items (Guinea pig fur), with 9 items in each stack, in two distinct stockpiles (Stockpile zone 1 and Stockpile zone 3) with similar storage settings.
The two stacks of items have different HP: 60/60 for the stack in stockpile zone 1, and 56/60 for the stack in stockpile zone 3.

With one of my pawns selected, I right-click on one of the stacks to access the contextual menu, and order my pawn to merge the two stacks.

Expected result:
One selectable entry in the stack contextual menu to order my pawn to merge the two stacks.

Actual result:
No selectable entry to give an order to my pawn.
Only an informative entry: "Cannot merge guinea pig fur: No stack available to merge into".

Steps to reproduce:
Have two stack of identical items in two distinct stockpiles with similar storage settings.

On the same save, this is reproducible with two stacks of granite blocks of 70 and 74 items each.

Savefile:
https://drive.google.com/open?id=1Hl0l-UPPTPgdEF4O4cvkuebCqsc94WsE

Log File:
I use RimWorld with Steam, but the Steam log file is way older (2020/02/22) than my current game where I had this issue (2020/03/02). So I joined both the Steam log file and non-Steam log file.

Additional attachments:
Here are some screenshots showing the contextual menu with the actual entry, the stacks details, and the stockpile zones settings : https://drive.google.com/open?id=1i-d-t-VkbZlfZBV_ujnWhQqZYcg_gP_B

[Flu007]

I think this is normal? Way I understood it, items need to be in the same stockpile in order to be mergeable.

[iforgotmysocks]

I think this is normal? Way I understood it, items need to be in the same stockpile in order to be mergeable.

^

In order to get ur items stacked assign one of the piles with a higher priority, items will then be stacked in that pile. Stacking via context menu is only possible within the same zone.

[Belp]

Oh yeah, you're right.
I thought that I saw that option with stacks in two distinct stockpiles, but that must have been in the same stockpile.
Sorry for the inconvenience 

That being said, the only option requires quite a lot of micromanagement.
Any plans to have pawns automatically kind of defragment the stockpiles?

[Ark]

They already do merge items in the same stockpile automatically, but it's a really low-priority job.
I don't think it would be a good idea to haul stuff back and forth between equal-priority stockpiles, just to merge them. You would end up with medicine from prison getting hauled to hospital, mortar shells being juggled etc.

[Belp]

You would end up with medicine from prison getting hauled to hospital, mortar shells being juggled etc.

I didn't think of this case. Now that you mention it, it would not make much sense.

But in the case of my savefile, the two stockpiles are in the same room. In my case, I think it would make more sense to merge items between equal-priority stockpiles.
But I guess it depends on the configuration of the room, its size, the distance between the stockpiles, etc...