sitest | Prometheus exporter to test HTTP websites | Analytics library

I'm not a database expert at all. I need your help.

Some context first:

I need to post a Work Order to a REST server. When I get the WO, I know the customer name, the site name where the job must be executed, and the full site address. Site name I receive could be like:

• George 1 (The correct name)
• George1
• Georg 1

If I'm posting the WO to the server, the request is sometimes rejected because the site name is not 100% exactly the same as stored on the server.

To propose a better user experience, I created a local SQLite table that I can synchronize with the REST server. Before posting the WO, I'd like to give the opportunity to the user to correct the site name if a direct match is not found by proposing a dropdown list of the best possible matches.

At this point, my code is: (This may not be the best way to do it)

I'm getting the error

Multiplicity constraint violated. The role 'CollectionSite_CollectionSiteOption_Target' of the relationship 'DatabaseRefreshRecovery.Data.CollectionSite_CollectionSiteOption' has multiplicity 1 or 0..1.

and I can't figure out what is the cause.

From the Google results I found, it seems that this error is associated with updating a detached entity. I'm doing neither. I'm getting this error while retrieving data from the database.

I'm using EF6 in a desktop application. The entities are a one-to-one relationship where the SiteID serves as the primary key in the parent table (CollectionSite) and the primary and foreign key in the child table (CollectionSiteOption).

Below are my classes, line of code causing the error, and the context portion for the classes. Does anyone see anything I may have missed or any idea what may be going on?

CollectionSite class: