Fix Custom Google Map

I have an existing google map which loads custom map tiles and the map worked fine for more than a year, but late last year, I noticed my background had been "covered" with a light grey "Fill". It appears the custom background I had set previously has been covered by some sort of "Default" grey colored "Overlay". When the map loads, I can still see my old background for a brief moment, but then it is covered by the grey overlay and then my custom maptiles are loaded onto the map as expected, but, without my custom "Water" background being visible. I just need to get this sorted out so the overlay is gone and my background is once again visible. I believe a change has been made to the Google maps api as I was including the .js file directly from google. Nothing had been changed on my end, and I had multiple copies which are all acting the same way and none have been changed. Possibly a css issue?? The included picture shows part of the map with my custom map tiles loaded, but with my "water" background being covered by the grey overlay.