Hi there.
I have had the opposite experience! Before I began I was snacking all evening and every bedtime had to gulp gallons of Gaviscon to relieve the heartburn.
Now I mostly stick to Green days, but have also tried not to eat much after about 7pm and my heartburn has disappeared.
Our bodies do take time to adapt to changes in diet so give it time - but I would also avoid eating too late if, like mine, the indigestion comes on at night.