Web Viewer with Google Maps rendering only part of the map issue

[cat traveller]

Hi everyone, 

I am loading lat and lng coordinates from logged from Filemaker Go into our Filemaker that we use on the Mac into the webviewer displayed in a popup card window. Unfortunately, only part of the map is shown 

on the webviewer. I seem to be missing something. Played around with the different refresh and pause settings but nothing works. However, if I load the viewer into its card window 3 times, it shows correctly.

In attach my code and how it renders - would anyone know what the issue is? It renders fine in filemaker go....

Thank you