If you can't find some ASINs in your catalog or, on the contrary, you have ASINs that should not be in it, it means that you might have not the same catalog linked to your Vendor Central and Advertising Console.

The first thing to check is if you can find the ASINs in the Advertising console. Enter an Ad Group and try adding them :

Once you've confirmed the ASIN issue, you need to go to "Settings" > "Account access & settings" :

Then go to "Linked accounts" and check the ID under "Account name" :

Compare the ID with what you have in Vendor Central under "Advertising" > "Advertising at Amazon" :

If the IDs are identical, the issue is not there. Otherwise, try linking the right Vendor Central account :

If you can't, contact Amazon's support and request their help.