Hi Kyle,
Problems again (and this time I think it is a bug on your side).
So, trigger works and also the variables BUT not the activity action. The link is indeed taken from the trigger and inputted into the URL field, the problem is that Activity firstly does not seem to recognise that it is an INTERNAL URL (ie without the domain name), secondly it does not auto-fill the Thumbnail, title and meta-data like it does for the shared links (using the URL Share button in the Activity module).
I have attached the screenshots of how I have set it up.
All I want is that I provide an internal link to activity using auto action and it does all the things as if I had shared it using the URL button on the Activity Module.
EDIT: I tried it with putting different variables into the Image URL using the Auto Actions but it steadfastly refused to save the links