AEM 6.5.2 - issue with cache invalidation of an alias

Hello,

Recently since upgrading to 6.5, i've been having issues with cache invalidation not happening on aliased locations during deactivation events.

eg. -  I have /content/test/en_US/testpage.html that would have an alias to /content/test/en/testpage.html

On activation of this page, I see the flush agent behaving properly for both the aliased and non aliased location.

However, if I then go to deactivate this page -

The page is deactivated and invalidated on the non aliased location, but remains in cache at the aliased location.

I do have the alias update checkbox selected on my flush agent on the publisher.

Any ideas what might cause this?