Data validation disappears with multiple worksheet auto update

[Keiralea]

Hello,

I have a worksheet that I want to do 2 things; 1 of which I have managed but now I have an error re my drop down lists which is my 2 goal of the spreadsheet:

1. I have a main worksheet, where I enter and update rows. Depending on the answer in Column N, all of the corresponding data in that row is auto updated in the subsequent worksheets. That is perfect and I am happy with it.

2. I would like the main worksheet to have drop down lists to choose from [including Column N]. Normally I have no problem adding these lists, but when I do now after I got it to auto fill, I cannot save it as I receive an error message that states the data validation is refered in other values.

Can someone help me with my objective 2 please? Are my drop down lists broken because of my auto fill to the other worksheets?

My ideal world is the drop down list + auto update the worksheets.

Many thanks!

[Keiralea]

This is my file:

I want columns A, B C and N to have drop down. Coloumn N cell values are what populates the subsequent worksheets.

Thanks!