Before going any further, please take a look at my current setup below:
So, I've tried to create trim guides on every corner of the pages (I have my own reason for doing this instead of creating trim guides automatically). Obviously, I put the guides in master page, so it can be repeated on every page.
On page 2, the guides are perfectly aligned on every corner of the page. Take a look at the picture below:
But, on page 1, the guides are taking the most right side of the page as their center. So there are only 2 guides, instead of 4.
WHAT GIVES? This is so weird because I've created this kind of guides in another InDesign file (a long time ago) and the guides are still working just fine when I reopened the file. I've also tried to make the master page A as 2-pages spread, and creating the guides on both pages, but it gives the same result. Could you guys help me solving this problem? Thank you in advance.
You only have single page masters. This is a facing spreads document and the masters should be set up the same way and then applied properly.
I don't think that's the whole story -- a single master can be used on either side of the spine. I suspect the Page toll was used at some point to move the page.
Could be but if the OP posts the file somewhere it would be a lot easier to tell.