When you give a flower, click the "back to question list" just above the post you are looking at. Your flower will be there. Here's another * for you. Otherwise, if after you have read a posting and you and use your browser back arrow you can give a flower then and it will stay.
Yes, the flowers do work. Sometimes they appear to disappear but they really don't. Two of us gave you flowers and your number changed. You are probably using the browser back button instead of using the links on the site.
Flowers work as long as you don't use the reload last page function.