Exclude newest post from flex block / duplicate posts issue

Hi,

on my homepage I have three main blocks of posts:

block A – main flex block 4 which shows the latest published post, regardless of category/tag/author etc.
block B – flex block 4, which shows 3 latest posts from few selected categories (e.g. X, Y) that are usually more articles written in more depth
block C – flex block 5, which lists 3 latest posts from a single category (e.g. Z), which are usually basic news posts

There’s no offset in any of them, but I encounter a repeating problem. Because block A is displaying whatever was posted lately, that same post will appear in either B or C blocks, depending on the latest posts’ category.
Meaning if I post something in category X, it appears under blocks A and B; if I post something in category Z, it will appear in blocks A and C.

I can’t use offset in B or C blocks as one of them will wrongly remove a post that’s not displayed in A, i.e. when latest post is category X, block C will wrongly offset one post from category Z which then isn’t displayed anywhere.

What do you suggest I do to add some form of logical non-duplication, ideally doable directly through Cloud templates which will ensure it not breaking in the future?

Using latest Newspaper and WP versions.

Thanks!

Thank you very much Anamaria, this solved the issue fully!