Not being awarded gems for defense

In the past 24 hours my defense (according to heat map) has been attacked with a lot of invocations.  However I have not received any gems is there an issue with this?    

Hi,

Your heatmap displays the data for the last 20 attacks over a certain period of time.

If you didn’t lose trophies nor earn gems in the meantime it means you didn’t get additional attacks where people spent gems and took trophies from you.

You know if we had battle logs these questions would not have to be asked…