different margins that I don't wanted

[alexanders16782545]

Dear Adobe Support Community,

I choosed in the Document Setup the margins inside and outside both 12 mm, but anyway they are different on the left and the right page.
Also in Layout - Margins and Columns - I choosed both 12 mm.
The left page is right, but on the right page, the margins are a little bit bigger. 
Is there any other menu, where I have to proof the margins, or what did I make possibly wrong?
Kind regards, Alexander (Germany)

[alexanders16782545]

One addition to my post: 
On same right pages, the margins are correct, on some not.

[alexanders16782545]

Ok, sorry, I have to modify the question: I can correct the margins in Layout - Margins and Columns (maybe before I hadn't really selected the right page).
My new question:
How can I quickly change all margins to 12 mm (on some pages they are 12,7 mm), so that I don't have to do this on every wrong page particularly? On the masterpage they are already 12 mm.
Kind regards,
Alexander

[alexanders16782545 · Accepted solution]

Sorry again, I solved the problem.
I forgot again to CLICK ON the master page to really select it, before I set the right page margins in the Layout - Margins and Columns - Menu.