I see the issue on the second page you sent. From the code i'm not readily seeing any issues at all, however would you mind allowing me to have access to the site so that I can have a deeper look ?
I believe the issue goes beyond that just the empty fields, from my previous post you can see that the map markers show up fine when I changed the API Key.
What happens when an address is empty the marker will not show up at all.
We believe that the problem is not the API key because the markers show correctly in some pages, including the page that you captured.
We did try to remove all the caches and press "Check API" key button. Everything is fine.
The markers do not show up on this specific page below. hidden link
We tried to reduce the items and retained only 4 items. Each of them has a correct Map field value and can be shown in their individual page.
I noticed the issue was how you were placing the map on the page, as well as the marker. See Screenshot.
If you look at the screenshot you notice that you are loading the map markers before the map. Also not just loading the marker before the map but the marker is in pad-last index where no data is being passed.
To fix this I placed the map shortcode before the <wpv-loop></wpv-loop> tags and the marker shortcode inside the content template for this view so that it will load the markers onto the map.
So to set this clear it is a case where you are loading the markers before the map, when it should be loading the map before the markers.