If the controls are missing when using the Google Maps API, various articles repeatedly point to the styling of the <img> tag, suggesting that the maximum width should be set to "none" (max-width: none).
However, this does not help much if the controls are not generated in the first place and are therefore already missing from the source code. In our project, an outdated prototype.js was responsible for this. Updating the Prototype JavaScript library from version 1.6.0.2 to version 1.7.2 therefore solved the problem. The controls were then generated again and displayed as expected.
