URGENT - Display feed based on user ID

The work has been mostly done by us. We then looked to outsource the final piece of the jigsaw puzzle which looks like the last developer has struggled to achieve. It should be pretty straightforward.

We have setup a custom field which allows us to match candidates to employers, this field returns a value of the users ID's that have been matched. We have then setup a page inside WordPress which is using a hard-coded template. This runs a query to display all candidates that have matched the current users ID. When manually inputting the users ID into the template, the candidates display correctly, however when using the get_current_user_id() function, it doesn't work.

We need this resolved today ideally. Shouldn't be any more than an hour's work.