Just created a test file for anyone who wants to verified this issue, but I'm 100 percent sure GetLayoutObjectAttribute will not work if you run it on server via PSOS.
I though the issue was with the WAN server taking too long to sort, but I moved the following fie to my local server and I get the same issue. If I run the script without PSOS works fine on both servers.
Then I thought the issue was a relational design problem....created a flat file and I get the same result. What's an another way to insert a filemaker chart into a container field without using GetLayoutObjectAttribute ???
See attachment for test file...it auto logs has guest with full access...thank you.