Tables :: Relationships Between Linked Tables

I have one database called asset management. It consists of one main table called cyber assets. Most fields in this table are linked to a manually created lookup table inorder to restrict user input. There are also two additional, none lookup, tables used to list a) the IP addresses (there can be more than one) and b) another similar 1 to many type table. Basically this DB is used to manage basic cyber asset data, excluding most items related to configuration management.

So, this above DB serves the purposes of asset management. Now I essentially need a similar DB for Patch Management. What I've done for this is to assess each patch initially (i.e. just by looking at the patch title and determining if we even have any of those device. i.e. this assessment is not based on OS, model number... just a general 'may' or 'may not' be applicable). Here's what this SEPARATE DB looked like:

Since each patch is essentially assessed against itself, or maybe a better way to describe it is against the users memory of what we do and don't have, only a single table and form was needed.

So now we've been thru this process and the DB is filled, all initial assessments are complete. The next step is to take all the ones that are applicable to our company (based on the initial assessment when you answer, yes is applicable) and do assessments based on each device we have.So what I want to do is to link the two DBs on a new table called Patches_by_device, inside the original patching DB... so the relationships would look like this:

But as you can see, the linked table CYBER_ASSETS has some sort of undefined relationship type, which is causing my issues.So the next thing I did was to autocreate a form based on the Patches_by_device table, and here's the result.I need to change the patch_key to the Patch_ID+Patch description+URL, etc, and to change the device key to the the UNID+IP+functional description, etc...so I changed the form record source like this:

Now I should be able to change the control source of the Patch_key and Device_key to more useful information. so I changed: Patch_key control source to Patch_ID and Device_key control source to UNID (which is in the cyber assets table)

As you can see, it worked for the patch_ID but not the UNID which is part of the linked table.Must it be within one DB, because we have a ton of other modules to implement (e.g. config management, vulnerability assessments, audit stuff, and more...) and I'd like all these to be in individual DBs, all liked back to the main cyber_assets/Asset management DB.I've considered just modifying that patch table so that each device has its own column heading in the table, but this will cause issues when new devices are added.