First of all, nice site! The overall design, look and feel is really good.
So part of the issue might be that a couple of your containers have a css overflow property of auto. Realistically, you don’t want to allow for overflow, because if your design is truly responsive, then it should respond at different view sizes.Additionally, allowing for overflow is a pain, because now you have the main screen scrolling and then each container scrolls as well. It’s not user-friendly.
Even though removing the overflow means that the overall length of the scroll on your site is extended, it’s much better this way and allows for more natural scrolling and interaction to occur.
Note: I tested this on my Android phone with the Google Chrome browser.