Structured reference does not work on merged cells

Hi,

I have interesting issue in Excel, i will do my best to explain it thoroughlt.

I have two Sheets: Sheet1 and Sheet2

On 1st Sheet2 I have table named Table1.

I am trying to make cell C7 in Sheet1 reference to Table1 using VLOOKUP as shown in picture below. And this works.

But when i try to to the same thing on two merged cells (C12 and D12), my formula does not automatically work, see screenshots below.

1st screenshot is as i am writing formula for cell C7 in Sheet1, it works, it give me reference automatically.

Next screenshot show it does not work on other cell in Sheet1 which is merged (C12D12), it does not give me reference to Table and this is anoying, it really slows down. 

What is even more interesting is that if i use merged cells that are on the same Sheet as Table, Sheet2, it works. See screenshot below.

I don't get it, is there something i don't see?

Tryed on Mac and Windows, same thing.

PS

I can adjust formula manually, it works, but why doesn't it work automatically?

Thank you