Sitecore experience editor site does not resolve to sc_site

Question

When trying to preview an item the resolved site and context do not belong to the correct site chosen in our multisite setup.

Rendering.SiteResolving is true.

Rendering.SiteResolvingMatchCurrentSite is true.

Preview.ResolveSite is true.

sc_site is correctly named as per site config.

If I edit the site configuration so the names don't match then I correctly get an error, and reverting gets me a successful load but the wrong site has been resolved. So my problem is that my multisite setup does not resolve the correct site when previewing despite the config being set up for it.

I use Sitecore 9.1, so many of the older fixes do not apply. (I assume) No related errors are thrown in the log, and I have been unable to figure out how to debug the site resolving process. I could use some pointers on where and how to find the error, so far I've tried to debug from the Sitecore context to try and catch when the context.Site object gets assigned but no luck. Any help is appreciated.

Edit: This is an example of one of the sites:

<site name="abstract-site-definition"
        virtualFolder="/"
        physicalFolder="/"
        startItem="/FrontPage"
        database="web"
        domain="extranet"
        allowDebug="true"
        cacheHtml="true"
        htmlCacheSize="50MB"
        enablePreview="true"
        enableWebEdit="true"
        enableDebugger="true"
        disableClientData="false"
        formsRoot="{GUID}"
        scheme="https"
        externalPort="80"
        enableItemLanguageFallback="true"
        enableFieldLanguageFallback="true"
        />
<site name="name1" patch:before="site[@name='website']"
            inherits="abstract-site-definition"
            hostName="hostname1"
            targetHostName="hostname1"
            language="se"
            rootPath="/sitecore/content/itemName1/"
      />

Answer 1

I believe the context is set by the users login so if you log in to mysite1/sitecore that will be the context that the Experience Editor works in. You can of course change it using the nav bar but not really what you are looking for

Answer 2

I faced same issue for my Multisite website where Multiple domains used (Pipe separated) in Site definition Host name. I did below mentioned four config settings and its resolved.

In Sitecore.config set,

Rendering.SiteResolving is true.

Rendering.SiteResolvingMatchCurrentSite is true.

Preview.ResolveSite is true.

In Sitedefinition.config

Set specific TargetHostName for every site.

Hope that helps.